{"id":30647,"date":"2025-07-10T13:38:27","date_gmt":"2025-07-10T06:38:27","guid":{"rendered":"https:\/\/interdata.vn\/blog\/?p=30647"},"modified":"2025-07-10T13:38:27","modified_gmt":"2025-07-10T06:38:27","slug":"legacy-code-la-gi","status":"publish","type":"post","link":"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/","title":{"rendered":"Legacy Code l\u00e0 g\u00ec? C\u00e1ch x\u1eed l\u00fd m\u00e3 ngu\u1ed3n c\u0169 t\u1eeb A-Z cho Developer"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_84 counter-hierarchy ez-toc-counter ez-toc-white ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">N\u1ed8I DUNG<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 eztoc-toggle-hide-by-default' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Legacy-Code-la-gi\" >Legacy Code l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Dau-hieu-nhan-biet-ban-dang-lam-viec-voi-Legacy-Code\" >D\u1ea5u hi\u1ec7u nh\u1eadn bi\u1ebft b\u1ea1n \u0111ang l\u00e0m vi\u1ec7c v\u1edbi Legacy Code<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Tai-sao-Legacy-Code-lai-tro-thanh-%E2%80%9Cnoi-am-anh%E2%80%9D-cua-lap-trinh-vien\" >T\u1ea1i sao Legacy Code l\u1ea1i tr\u1edf th\u00e0nh &#8220;n\u1ed7i \u00e1m \u1ea3nh&#8221; c\u1ee7a l\u1eadp tr\u00ecnh vi\u00ean?<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Kho-doc-va-kho-hieu\" >Kh\u00f3 \u0111\u1ecdc v\u00e0 kh\u00f3 hi\u1ec3u<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Thieu-kiem-thu-Lack-of-Tests\" >Thi\u1ebfu ki\u1ec3m th\u1eed (Lack of Tests)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Rui-ro-cao-khi-thay-doi\" >R\u1ee7i ro cao khi thay \u0111\u1ed5i<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Chi-phi-bao-tri-tang-cao\" >Chi ph\u00ed b\u1ea3o tr\u00ec t\u0103ng cao<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Hieu-suat-kem-va-kho-mo-rong\" >Hi\u1ec7u su\u1ea5t k\u00e9m v\u00e0 kh\u00f3 m\u1edf r\u1ed9ng<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Kho-tich-hop-voi-cong-nghe-moi\" >Kh\u00f3 t\u00edch h\u1ee3p v\u1edbi c\u00f4ng ngh\u1ec7 m\u1edbi<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Su-khac-nhau-giua-Legacy-Code-vs-New-Code\" >S\u1ef1 kh\u00e1c nhau gi\u1eefa Legacy Code vs New Code<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Cac-phuong-phap-tiep-can-xu-ly-Legacy-Code-hieu-qua\" >C\u00e1c ph\u01b0\u01a1ng ph\u00e1p ti\u1ebfp c\u1eadn &amp; x\u1eed l\u00fd Legacy Code hi\u1ec7u qu\u1ea3<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Refactoring-Tai-cau-truc-ma-nguon\" >Refactoring (T\u00e1i c\u1ea5u tr\u00fac m\u00e3 ngu\u1ed3n)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Viet-kiem-thu-Unit-Test-cho-Legacy-Code\" >Vi\u1ebft ki\u1ec3m th\u1eed (Unit Test) cho Legacy Code<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#-Chien-luoc-%E2%80%9CStrangler-Fig-Pattern%E2%80%9D\" >\u00a0Chi\u1ebfn l\u01b0\u1ee3c &#8220;Strangler Fig Pattern&#8221;<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Giai-quyet-%E2%80%9CCon-no-ky-thuat%E2%80%9D-Technical-Debt\" >Gi\u1ea3i quy\u1ebft &#8220;Con n\u1ee3 k\u1ef9 thu\u1eadt&#8221; (Technical Debt)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Cac-cong-cu-hien-dai-ho-tro-Legacy-Code\" >C\u00e1c c\u00f4ng c\u1ee5 hi\u1ec7n \u0111\u1ea1i h\u1ed7 tr\u1ee3 Legacy Code<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Cong-cu-phan-tich-ma-tinh-Static-Code-Analysis-Tools\" >C\u00f4ng c\u1ee5 ph\u00e2n t\u00edch m\u00e3 t\u0129nh (Static Code Analysis Tools)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Khung-kiem-tra-tu-dong-Automated-Testing-Frameworks\" >Khung ki\u1ec3m tra t\u1ef1 \u0111\u1ed9ng (Automated Testing Frameworks)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Bo-cong-cu-va-nen-tang-di-chuyen-Migration-Toolkits-and-Platforms\" >B\u1ed9 c\u00f4ng c\u1ee5 v\u00e0 n\u1ec1n t\u1ea3ng di chuy\u1ec3n (Migration Toolkits and Platforms)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Cong-cu-tao-tai-lieu-Documentation-Generation-Tools\" >C\u00f4ng c\u1ee5 t\u1ea1o t\u00e0i li\u1ec7u (Documentation Generation Tools)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/#Loi-khuyen-cho-lap-trinh-vien-khi-doi-mat-voi-Legacy-Code\" >L\u1eddi khuy\u00ean cho l\u1eadp tr\u00ecnh vi\u00ean khi \u0111\u1ed1i m\u1eb7t v\u1edbi Legacy Code<\/a><\/li><\/ul><\/nav><\/div>\n<p>\u0110\u00e3 bao gi\u1edd b\u1ea1n c\u1ea3m th\u1ea5y lo l\u1eafng khi ph\u1ea3i s\u1eeda m\u1ed9t l\u1ed7i nh\u1ecf trong m\u1ed9t h\u1ec7 th\u1ed1ng l\u1edbn v\u00e0 c\u0169 k\u1ef9 ch\u01b0a? Vi\u1ec7c hi\u1ec3u v\u00e0 l\u00e0m ch\u1ee7 Legacy Code kh\u00f4ng ch\u1ec9 l\u00e0 m\u1ed9t k\u1ef9 n\u0103ng sinh t\u1ed3n, m\u00e0 c\u00f2n l\u00e0 m\u1ed9t c\u01a1 h\u1ed9i l\u1edbn \u0111\u1ec3 b\u1ea1n kh\u1eb3ng \u0111\u1ecbnh gi\u00e1 tr\u1ecb chuy\u00ean m\u00f4n. B\u00e0i vi\u1ebft n\u00e0y s\u1ebd gi\u1ea3i \u0111\u00e1p Legacy Code l\u00e0 g\u00ec, d\u1ea5u hi\u1ec7u nh\u1eadn bi\u1ebft, r\u1ee7i ro ti\u1ec1m \u1ea9n cho \u0111\u1ebfn 5 chi\u1ebfn l\u01b0\u1ee3c x\u1eed l\u00fd <a href=\"https:\/\/interdata.vn\/blog\/source-code-la-gi\/\">m\u00e3 ngu\u1ed3n<\/a> c\u0169 hi\u1ec7u qu\u1ea3 m\u00e0 InterData \u0111\u00e3 t\u1ed5ng h\u1ee3p cho b\u1ea1n. \u0110\u1ecdc ngay!<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Legacy-Code-la-gi\"><\/span>Legacy Code l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong><a href=\"https:\/\/interdata.vn\/blog\/legacy-code-la-gi\/\">Legacy Code<\/a> hay m\u00e3 ngu\u1ed3n c\u0169 <\/strong>l\u00e0 nh\u1eefng \u0111o\u1ea1n m\u00e3 c\u0169, th\u01b0\u1eddng \u0111\u01b0\u1ee3c vi\u1ebft b\u1eb1ng c\u00f4ng ngh\u1ec7 l\u1ed7i th\u1eddi ho\u1eb7c theo c\u00e1c ph\u01b0\u01a1ng ph\u00e1p kh\u00f4ng c\u00f2n \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng ph\u1ed5 bi\u1ebfn. M\u00e3 ngu\u1ed3n c\u0169 ;\u00e0 nh\u1eefng \u0111o\u1ea1n code, \u1ee9ng d\u1ee5ng ho\u1eb7c to\u00e0n b\u1ed9 h\u1ec7 th\u1ed1ng v\u1eabn \u0111ang mang l\u1ea1i gi\u00e1 tr\u1ecb cho doanh nghi\u1ec7p nh\u01b0ng l\u1ea1i c\u1ef1c k\u1ef3 kh\u00f3 \u0111\u1ec3 b\u1ea3o tr\u00ec, s\u1eeda \u0111\u1ed5i hay m\u1edf r\u1ed9ng.<\/p>\n<figure id=\"attachment_30663\" aria-describedby=\"caption-attachment-30663\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Legacy-Code-la-gi.jpg\" alt=\"Legacy Code l\u00e0 g\u00ec?\" width=\"800\" height=\"500\" class=\"size-full wp-image-30663\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Legacy-Code-la-gi.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Legacy-Code-la-gi-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Legacy-Code-la-gi-768x480.jpg 768w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Legacy-Code-la-gi-750x469.jpg 750w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-30663\" class=\"wp-caption-text\">Legacy Code l\u00e0 g\u00ec?<\/figcaption><\/figure>\n<p>Michael Feathers, t\u00e1c gi\u1ea3 cu\u1ed1n s\u00e1ch kinh \u0111i\u1ec3n &#8220;Working Effectively with Legacy Code&#8221;, \u0111\u00e3 \u0111\u01b0a ra m\u1ed9t \u0111\u1ecbnh ngh\u0129a s\u1eafc b\u00e9n v\u00e0 tr\u1edf th\u00e0nh ti\u00eau chu\u1ea9n trong ng\u00e0nh: \u201cLegacy code is simply code without tests\u201d (M\u00e3 ngu\u1ed3n c\u0169 \u0111\u01a1n gi\u1ea3n l\u00e0 m\u00e3 ngu\u1ed3n kh\u00f4ng c\u00f3 c\u00e1c b\u00e0i ki\u1ec3m th\u1eed t\u1ef1 \u0111\u1ed9ng).<\/p>\n<p>\u0110\u1ecbnh ngh\u0129a n\u00e0y r\u1ea5t m\u1ea1nh m\u1ebd v\u00ec n\u00f3 kh\u00f4ng t\u1eadp trung v\u00e0o tu\u1ed5i \u0111\u1eddi c\u1ee7a code. M\u1ed9t \u0111o\u1ea1n code vi\u1ebft t\u1eeb tu\u1ea7n tr\u01b0\u1edbc nh\u01b0ng kh\u00f4ng c\u00f3 test, kh\u00f3 thay \u0111\u1ed5i, c\u0169ng ch\u00ednh l\u00e0 legacy code. Ng\u01b0\u1ee3c l\u1ea1i, m\u1ed9t h\u1ec7 th\u1ed1ng 10 n\u0103m tu\u1ed5i nh\u01b0ng c\u00f3 b\u1ed9 test \u0111\u1ea7y \u0111\u1ee7, t\u00e0i li\u1ec7u r\u00f5 r\u00e0ng v\u00e0 c\u1ea5u tr\u00fac t\u1ed1t th\u00ec kh\u00f4ng ph\u1ea3i l\u00e0 legacy code.<\/p>\n<p>H\u00e3y h\u00ecnh dung n\u00f3 nh\u01b0 m\u1ed9t c\u1ed7 m\u00e1y c\u00f4ng nghi\u1ec7p v\u1eabn \u0111ang ho\u1ea1t \u0111\u1ed9ng t\u1ed1t, nh\u01b0ng m\u1ecdi con \u1ed1c \u0111\u1ec1u \u0111\u00e3 b\u1ecb h\u00e0n ch\u1ebft. B\u1ea1n kh\u00f4ng th\u1ec3 th\u00e1o ra \u0111\u1ec3 b\u1ea3o d\u01b0\u1ee1ng hay n\u00e2ng c\u1ea5p n\u1ebfu kh\u00f4ng c\u00f3 nguy c\u01a1 l\u00e0m h\u1ecfng c\u1ea3 c\u1ed7 m\u00e1y.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Dau-hieu-nhan-biet-ban-dang-lam-viec-voi-Legacy-Code\"><\/span>D\u1ea5u hi\u1ec7u nh\u1eadn bi\u1ebft b\u1ea1n \u0111ang l\u00e0m vi\u1ec7c v\u1edbi Legacy Code<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Vi\u1ec7c nh\u1eadn di\u1ec7n s\u1edbm Legacy Code l\u00e0 r\u1ea5t quan tr\u1ecdng \u0111\u1ec3 c\u00f3 th\u1ec3 \u0111\u01b0a ra c\u00e1c chi\u1ebfn l\u01b0\u1ee3c x\u1eed l\u00fd ph\u00f9 h\u1ee3p. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 nh\u1eefng d\u1ea5u hi\u1ec7u r\u00f5 r\u00e0ng cho th\u1ea5y b\u1ea1n \u0111ang l\u00e0m vi\u1ec7c v\u1edbi m\u00e3 ngu\u1ed3n c\u0169:<\/p>\n<ul>\n<li><strong>Thi\u1ebfu ho\u1eb7c kh\u00f4ng c\u00f3 b\u00e0i ki\u1ec3m th\u1eed t\u1ef1 \u0111\u1ed9ng<\/strong>: \u0110\u00e2y l\u00e0 d\u1ea5u hi\u1ec7u r\u00f5 r\u00e0ng nh\u1ea5t. N\u1ebfu b\u1ea1n kh\u00f4ng th\u1ec3 ch\u1ea1y m\u1ed9t b\u1ed9 ki\u1ec3m th\u1eed t\u1ef1 \u0111\u1ed9ng (automated tests) \u0111\u1ec3 x\u00e1c minh h\u00e0nh vi c\u1ee7a m\u00e3 ngu\u1ed3n, th\u00ec \u0111\u00f3 g\u1ea7n nh\u01b0 ch\u1eafc ch\u1eafn l\u00e0 Legacy Code.<\/li>\n<li><strong>Kh\u00f3 kh\u0103n trong vi\u1ec7c th\u00eam t\u00ednh n\u0103ng m\u1edbi<\/strong>: M\u1ed7i khi c\u1ea7n th\u00eam m\u1ed9t t\u00ednh n\u0103ng m\u1edbi, qu\u00e1 tr\u00ecnh tr\u1edf n\u00ean ph\u1ee9c t\u1ea1p m\u1ed9t c\u00e1ch b\u1ea5t th\u01b0\u1eddng. L\u1eadp tr\u00ecnh vi\u00ean ph\u1ea3i d\u00e0nh nhi\u1ec1u th\u1eddi gian \u0111\u1ec3 hi\u1ec3u code hi\u1ec7n c\u00f3 v\u00e0 t\u00ecm c\u00e1ch &#8220;nh\u00e9t&#8221; t\u00ednh n\u0103ng m\u1edbi v\u00e0o m\u00e0 kh\u00f4ng ph\u00e1 v\u1ee1 nh\u1eefng ph\u1ea7n kh\u00e1c.<\/li>\n<li><strong>S\u1ee3 h\u00e3i khi thay \u0111\u1ed5i<\/strong>: B\u1ea1n ho\u1eb7c \u0111\u1ed3ng nghi\u1ec7p c\u00f3 c\u1ea3m gi\u00e1c lo l\u1eafng, s\u1ee3 h\u00e3i khi ph\u1ea3i ch\u1ec9nh s\u1eeda m\u1ed9t ph\u1ea7n n\u00e0o \u0111\u00f3 c\u1ee7a m\u00e3 ngu\u1ed3n, ngay c\u1ea3 nh\u1eefng thay \u0111\u1ed5i nh\u1ecf. \u0110i\u1ec1u n\u00e0y xu\u1ea5t ph\u00e1t t\u1eeb vi\u1ec7c kh\u00f4ng bi\u1ebft r\u00f5 t\u00e1c \u0111\u1ed9ng c\u1ee7a thay \u0111\u1ed5i \u0111\u00f3.<\/li>\n<li><strong>Thi\u1ebfu t\u00e0i li\u1ec7u ho\u1eb7c t\u00e0i li\u1ec7u \u0111\u00e3 l\u1ed7i th\u1eddi<\/strong>: T\u00e0i li\u1ec7u v\u1ec1 m\u00e3 ngu\u1ed3n (n\u1ebfu c\u00f3) kh\u00f4ng \u0111\u1ea7y \u0111\u1ee7, kh\u00f4ng ch\u00ednh x\u00e1c, ho\u1eb7c \u0111\u00e3 qu\u00e1 c\u0169 so v\u1edbi t\u00ecnh tr\u1ea1ng hi\u1ec7n t\u1ea1i c\u1ee7a code. \u0110i\u1ec1u n\u00e0y khi\u1ebfn vi\u1ec7c hi\u1ec3u h\u1ec7 th\u1ed1ng tr\u1edf n\u00ean kh\u00f3 kh\u0103n h\u01a1n.<\/li>\n<li><strong>S\u1ef1 ph\u1ee9c t\u1ea1p kh\u00f4ng c\u1ea7n thi\u1ebft<\/strong>: M\u00e3 ngu\u1ed3n ch\u1ee9a nhi\u1ec1u \u0111o\u1ea1n code r\u01b0\u1eddm r\u00e0, l\u1eb7p l\u1ea1i, ho\u1eb7c s\u1eed d\u1ee5ng c\u00e1c c\u1ea5u tr\u00fac ph\u1ee9c t\u1ea1p m\u00e0 kh\u00f4ng c\u00f3 l\u00fd do r\u00f5 r\u00e0ng. C\u00e1c h\u00e0m, l\u1edbp (classes) qu\u00e1 l\u1edbn, ch\u1ee9a qu\u00e1 nhi\u1ec1u tr\u00e1ch nhi\u1ec7m.<\/li>\n<li><strong>Ph\u1ee5 thu\u1ed9c v\u00e0o c\u00e1c th\u01b0 vi\u1ec7n ho\u1eb7c <a href=\"https:\/\/interdata.vn\/blog\/framework-la-gi\/\">framework<\/a> l\u1ed7i th\u1eddi<\/strong>: H\u1ec7 th\u1ed1ng s\u1eed d\u1ee5ng c\u00e1c phi\u00ean b\u1ea3n c\u0169 c\u1ee7a th\u01b0 vi\u1ec7n ho\u1eb7c framework m\u00e0 kh\u00f4ng c\u00f2n \u0111\u01b0\u1ee3c h\u1ed7 tr\u1ee3 ho\u1eb7c c\u00f3 l\u1ed7 h\u1ed5ng b\u1ea3o m\u1eadt. Vi\u1ec7c n\u00e2ng c\u1ea5p ch\u00fang th\u01b0\u1eddng r\u1ea5t kh\u00f3 kh\u0103n do s\u1ef1 t\u01b0\u01a1ng th\u00edch.<\/li>\n<li><strong>Th\u1eddi gian build\/deploy l\u00e2u<\/strong>: Qu\u00e1 <a href=\"https:\/\/interdata.vn\/blog\/compiler-trinh-bien-dich-la-gi\/\">tr\u00ecnh bi\u00ean d\u1ecbch<\/a> (build) ho\u1eb7c tri\u1ec3n khai (deploy) \u1ee9ng d\u1ee5ng m\u1ea5t qu\u00e1 nhi\u1ec1u th\u1eddi gian, l\u00e0m ch\u1eadm chu tr\u00ecnh ph\u00e1t tri\u1ec3n.<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Tai-sao-Legacy-Code-lai-tro-thanh-%E2%80%9Cnoi-am-anh%E2%80%9D-cua-lap-trinh-vien\"><\/span>T\u1ea1i sao Legacy Code l\u1ea1i tr\u1edf th\u00e0nh &#8220;n\u1ed7i \u00e1m \u1ea3nh&#8221; c\u1ee7a l\u1eadp tr\u00ecnh vi\u00ean?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Legacy Code mang theo nhi\u1ec1u v\u1ea5n \u0111\u1ec1 nghi\u00eam tr\u1ecdng, kh\u00f4ng ch\u1ec9 \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn hi\u1ec7u su\u1ea5t l\u00e0m vi\u1ec7c c\u1ee7a l\u1eadp tr\u00ecnh vi\u00ean m\u00e0 c\u00f2n t\u00e1c \u0111\u1ed9ng ti\u00eau c\u1ef1c \u0111\u1ebfn chi ph\u00ed v\u00e0 ch\u1ea5t l\u01b0\u1ee3ng d\u1ef1 \u00e1n. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 nh\u1eefng l\u00fd do ch\u00ednh khi\u1ebfn n\u00f3 tr\u1edf th\u00e0nh &#8220;n\u1ed7i \u00e1m \u1ea3nh&#8221;:<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Kho-doc-va-kho-hieu\"><\/span>Kh\u00f3 \u0111\u1ecdc v\u00e0 kh\u00f3 hi\u1ec3u<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>M\u00e3 ngu\u1ed3n th\u01b0\u1eddng \u0111\u01b0\u1ee3c vi\u1ebft m\u00e0 kh\u00f4ng tu\u00e2n theo c\u00e1c quy t\u1eafc chu\u1ea9n, thi\u1ebfu b\u00ecnh lu\u1eadn (<a href=\"https:\/\/interdata.vn\/blog\/comments-wordpress-la-gi\/\">comments<\/a>), v\u00e0 c\u00f3 c\u1ea5u tr\u00fac ph\u1ee9c t\u1ea1p. \u0110i\u1ec1u n\u00e0y khi\u1ebfn l\u1eadp tr\u00ecnh vi\u00ean m\u1ea5t nhi\u1ec1u th\u1eddi gian \u0111\u1ec3 hi\u1ec3u \u0111\u01b0\u1ee3c lu\u1ed3ng ho\u1ea1t \u0111\u1ed9ng v\u00e0 m\u1ee5c \u0111\u00edch c\u1ee7a t\u1eebng ph\u1ea7n. Nghi\u00ean c\u1ee9u c\u1ee7a Robert C. Martin ch\u1ec9 ra r\u1eb1ng l\u1eadp tr\u00ecnh vi\u00ean d\u00e0nh ph\u1ea7n l\u1edbn th\u1eddi gian \u0111\u1ec3 \u0111\u1ecdc code h\u01a1n l\u00e0 vi\u1ebft code m\u1edbi.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Thieu-kiem-thu-Lack-of-Tests\"><\/span>Thi\u1ebfu ki\u1ec3m th\u1eed (Lack of Tests)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>M\u1ed9t trong nh\u1eefng \u0111\u1eb7c \u0111i\u1ec3m ph\u1ed5 bi\u1ebfn nh\u1ea5t c\u1ee7a Legacy Code l\u00e0 thi\u1ebfu c\u00e1c b\u00e0i ki\u1ec3m th\u1eed t\u1ef1 \u0111\u1ed9ng (unit tests, integration tests). Khi kh\u00f4ng c\u00f3 test, vi\u1ec7c thay \u0111\u1ed5i b\u1ea5t k\u1ef3 d\u00f2ng code n\u00e0o c\u0169ng ti\u1ec1m \u1ea9n r\u1ee7i ro r\u1ea5t cao. B\u1ea1n kh\u00f4ng th\u1ec3 ch\u1eafc ch\u1eafn r\u1eb1ng thay \u0111\u1ed5i n\u00e0y kh\u00f4ng l\u00e0m h\u1ecfng ch\u1ee9c n\u0103ng kh\u00e1c.<\/p>\n<figure id=\"attachment_30664\" aria-describedby=\"caption-attachment-30664\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Tai-sao-Legacy-Code-lai-tro-thanh-noi-am-anh-cua-lap-trinh-vien.jpg\" alt=\"T\u1ea1i sao Legacy Code l\u1ea1i tr\u1edf th\u00e0nh n\u1ed7i \u00e1m \u1ea3nh c\u1ee7a l\u1eadp tr\u00ecnh vi\u00ean\" width=\"800\" height=\"500\" class=\"size-full wp-image-30664\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Tai-sao-Legacy-Code-lai-tro-thanh-noi-am-anh-cua-lap-trinh-vien.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Tai-sao-Legacy-Code-lai-tro-thanh-noi-am-anh-cua-lap-trinh-vien-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Tai-sao-Legacy-Code-lai-tro-thanh-noi-am-anh-cua-lap-trinh-vien-768x480.jpg 768w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Tai-sao-Legacy-Code-lai-tro-thanh-noi-am-anh-cua-lap-trinh-vien-750x469.jpg 750w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-30664\" class=\"wp-caption-text\">T\u1ea1i sao Legacy Code l\u1ea1i tr\u1edf th\u00e0nh n\u1ed7i \u00e1m \u1ea3nh c\u1ee7a l\u1eadp tr\u00ecnh vi\u00ean<\/figcaption><\/figure>\n<h3><span class=\"ez-toc-section\" id=\"Rui-ro-cao-khi-thay-doi\"><\/span>R\u1ee7i ro cao khi thay \u0111\u1ed5i<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>V\u00ec thi\u1ebfu ki\u1ec3m th\u1eed v\u00e0 s\u1ef1 ph\u1ee9c t\u1ea1p, m\u1ed7i l\u1ea7n s\u1eeda ch\u1eefa ho\u1eb7c th\u00eam t\u00ednh n\u0103ng v\u00e0o Legacy Code \u0111\u1ec1u l\u00e0 m\u1ed9t canh b\u1ea1c. Nguy c\u01a1 ph\u00e1t sinh l\u1ed7i m\u1edbi, ho\u1eb7c &#8220;bug&#8221;, l\u00e0 r\u1ea5t l\u1edbn, d\u1eabn \u0111\u1ebfn vi\u1ec7c ph\u1ea3i d\u00e0nh nhi\u1ec1u th\u1eddi gian h\u01a1n cho vi\u1ec7c <a href=\"https:\/\/interdata.vn\/blog\/wordpress-debug-la-gi\/\">debug<\/a> v\u00e0 s\u1eeda ch\u1eefa. Chi ph\u00ed \u0111\u1ec3 s\u1eeda m\u1ed9t l\u1ed7i ph\u00e1t hi\u1ec7n mu\u1ed9n c\u00f3 th\u1ec3 cao g\u1ea5p 100 l\u1ea7n so v\u1edbi l\u1ed7i \u0111\u01b0\u1ee3c ph\u00e1t hi\u1ec7n s\u1edbm trong qu\u00e1 tr\u00ecnh ph\u00e1t tri\u1ec3n.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Chi-phi-bao-tri-tang-cao\"><\/span>Chi ph\u00ed b\u1ea3o tr\u00ec t\u0103ng cao<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Vi\u1ec7c duy tr\u00ec Legacy Code t\u1ed1n k\u00e9m h\u01a1n nhi\u1ec1u so v\u1edbi m\u00e3 ngu\u1ed3n m\u1edbi. L\u1eadp tr\u00ecnh vi\u00ean m\u1ea5t nhi\u1ec1u th\u1eddi gian h\u01a1n \u0111\u1ec3 hi\u1ec3u, s\u1eeda l\u1ed7i, v\u00e0 tri\u1ec3n khai t\u00ednh n\u0103ng m\u1edbi. \u0110i\u1ec1u n\u00e0y tr\u1ef1c ti\u1ebfp l\u00e0m t\u0103ng chi ph\u00ed nh\u00e2n s\u1ef1 v\u00e0 k\u00e9o d\u00e0i th\u1eddi gian ho\u00e0n th\u00e0nh d\u1ef1 \u00e1n.<\/p>\n<p>M\u1ed9t b\u00e1o c\u00e1o c\u1ee7a The Standish Group cho th\u1ea5y, ch\u1ec9 7% d\u1ef1 \u00e1n ph\u1ea7n m\u1ec1m \u0111\u01b0\u1ee3c ho\u00e0n th\u00e0nh \u0111\u00fang th\u1eddi h\u1ea1n v\u00e0 ng\u00e2n s\u00e1ch, m\u1ed9t ph\u1ea7n l\u1edbn nguy\u00ean nh\u00e2n \u0111\u1ebfn t\u1eeb s\u1ef1 ph\u1ee9c t\u1ea1p c\u1ee7a m\u00e3 ngu\u1ed3n hi\u1ec7n c\u00f3.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Hieu-suat-kem-va-kho-mo-rong\"><\/span>Hi\u1ec7u su\u1ea5t k\u00e9m v\u00e0 kh\u00f3 m\u1edf r\u1ed9ng<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Legacy Code th\u01b0\u1eddng kh\u00f4ng \u0111\u01b0\u1ee3c t\u1ed1i \u01b0u h\u00f3a cho hi\u1ec7u su\u1ea5t ho\u1eb7c kh\u1ea3 n\u0103ng m\u1edf r\u1ed9ng. Khi h\u1ec7 th\u1ed1ng c\u1ea7n x\u1eed l\u00fd l\u01b0\u1ee3ng <a href=\"https:\/\/interdata.vn\/blog\/big-data-la-gi\/\">d\u1eef li\u1ec7u l\u1edbn<\/a> h\u01a1n ho\u1eb7c ph\u1ee5c v\u1ee5 nhi\u1ec1u ng\u01b0\u1eddi d\u00f9ng h\u01a1n, n\u00f3 c\u00f3 th\u1ec3 tr\u1edf n\u00ean ch\u1eadm ch\u1ea1p v\u00e0 d\u1ec5 g\u1eb7p s\u1ef1 c\u1ed1. Vi\u1ec7c m\u1edf r\u1ed9ng c\u00e1c t\u00ednh n\u0103ng m\u1edbi c\u0169ng tr\u1edf n\u00ean kh\u00f3 kh\u0103n do ki\u1ebfn tr\u00fac l\u1ed7i th\u1eddi.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Kho-tich-hop-voi-cong-nghe-moi\"><\/span>Kh\u00f3 t\u00edch h\u1ee3p v\u1edbi c\u00f4ng ngh\u1ec7 m\u1edbi<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>C\u00e1c h\u1ec7 th\u1ed1ng Legacy Code th\u01b0\u1eddng \u0111\u01b0\u1ee3c x\u00e2y d\u1ef1ng tr\u00ean c\u00e1c c\u00f4ng ngh\u1ec7, th\u01b0 vi\u1ec7n, ho\u1eb7c framework c\u0169, kh\u00f4ng t\u01b0\u01a1ng th\u00edch v\u1edbi c\u00e1c gi\u1ea3i ph\u00e1p hi\u1ec7n \u0111\u1ea1i. \u0110i\u1ec1u n\u00e0y g\u00e2y kh\u00f3 kh\u0103n khi mu\u1ed1n t\u00edch h\u1ee3p v\u1edbi c\u00e1c h\u1ec7 th\u1ed1ng m\u1edbi ho\u1eb7c \u00e1p d\u1ee5ng c\u00f4ng ngh\u1ec7 ti\u00ean ti\u1ebfn nh\u01b0 AI, <a href=\"https:\/\/interdata.vn\/blog\/machine-learning-la-gi\/\">Machine Learning<\/a>, ho\u1eb7c <a href=\"https:\/\/interdata.vn\/blog\/microservices-la-gi\/\">microservices<\/a>.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Su-khac-nhau-giua-Legacy-Code-vs-New-Code\"><\/span>S\u1ef1 kh\u00e1c nhau gi\u1eefa Legacy Code vs New Code<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>M\u1eb7c d\u00f9 &#8220;Legacy Code&#8221; th\u01b0\u1eddng \u0111\u01b0\u1ee3c hi\u1ec3u l\u00e0 m\u00e3 ngu\u1ed3n c\u0169, nh\u01b0ng s\u1ef1 kh\u00e1c bi\u1ec7t c\u1ed1t l\u00f5i gi\u1eefa Legacy Code v\u00e0 New Code kh\u00f4ng ch\u1ec9 n\u1eb1m \u1edf tu\u1ed5i \u0111\u1eddi c\u1ee7a n\u00f3. Thay v\u00e0o \u0111\u00f3, n\u00f3 n\u1eb1m \u1edf kh\u1ea3 n\u0103ng thay \u0111\u1ed5i, duy tr\u00ec v\u00e0 m\u1edf r\u1ed9ng m\u00e3 ngu\u1ed3n \u0111\u00f3 m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3 v\u00e0 an to\u00e0n.<\/p>\n<p><strong>Legacy Code (M\u00e3 ngu\u1ed3n c\u0169\/di s\u1ea3n)<\/strong> l\u00e0 m\u00e3 ngu\u1ed3n m\u00e0 b\u1ea1n e ng\u1ea1i khi ph\u1ea3i thay \u0111\u1ed5i. N\u1ed7i s\u1ee3 n\u00e0y th\u01b0\u1eddng xu\u1ea5t ph\u00e1t t\u1eeb vi\u1ec7c thi\u1ebfu ki\u1ec3m th\u1eed, kh\u00f4ng c\u00f3 t\u00e0i li\u1ec7u r\u00f5 r\u00e0ng, c\u1ea5u tr\u00fac ph\u1ee9c t\u1ea1p, ho\u1eb7c ng\u01b0\u1eddi vi\u1ebft ban \u0111\u1ea7u \u0111\u00e3 kh\u00f4ng c\u00f2n l\u00e0m vi\u1ec7c. M\u1ed9t m\u00e3 ngu\u1ed3n c\u00f3 th\u1ec3 ch\u1ec9 v\u00e0i n\u0103m tu\u1ed5i nh\u01b0ng v\u1eabn \u0111\u01b0\u1ee3c coi l\u00e0 Legacy Code n\u1ebfu n\u00f3 g\u00e2y ra r\u1ee7i ro cao m\u1ed7i khi c\u00f3 s\u1ef1 can thi\u1ec7p.<\/p>\n<p><strong>New Code (M\u00e3 ngu\u1ed3n m\u1edbi)<\/strong> l\u00e0 m\u00e3 ngu\u1ed3n \u0111\u01b0\u1ee3c vi\u1ebft theo c\u00e1c ti\u00eau chu\u1ea9n hi\u1ec7n \u0111\u1ea1i, c\u00f3 t\u00e0i li\u1ec7u \u0111\u1ea7y \u0111\u1ee7, \u0111\u01b0\u1ee3c ki\u1ec3m th\u1eed k\u1ef9 l\u01b0\u1ee1ng v\u00e0 d\u1ec5 d\u00e0ng thay \u0111\u1ed5i, duy tr\u00ec. M\u1ee5c ti\u00eau c\u1ee7a New Code l\u00e0 t\u1ed1i \u01b0u h\u00f3a cho kh\u1ea3 n\u0103ng \u0111\u1ecdc, kh\u1ea3 n\u0103ng m\u1edf r\u1ed9ng v\u00e0 hi\u1ec7u su\u1ea5t trong t\u01b0\u01a1ng lai.<\/p>\n<p>D\u01b0\u1edbi \u0111\u00e2y l\u00e0 s\u1ef1 kh\u00e1c bi\u1ec7t ch\u00ednh c\u1ee7a Legacy Code vs New Code \u0111\u01b0\u1ee3c m\u00f4 t\u1ea3 d\u01b0\u1edbi b\u1ea3ng sau:<\/p>\n<table style=\"width: 100%; border-collapse: collapse; border: 1px solid #0D6EFD;\">\n<thead>\n<tr>\n<th style=\"background-color: #0d6efd; color: white; padding: 10px; text-align: center;\">\u0110\u1eb7c \u0111i\u1ec3m<\/th>\n<th style=\"background-color: #0d6efd; color: white; padding: 10px; text-align: center;\">Legacy Code<\/th>\n<th style=\"background-color: #0d6efd; color: white; padding: 10px; text-align: center;\">New Code<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\"><strong>Ki\u1ec3m th\u1eed<\/strong><\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">Thi\u1ebfu ho\u1eb7c kh\u00f4ng c\u00f3 c\u00e1c b\u00e0i ki\u1ec3m th\u1eed t\u1ef1 \u0111\u1ed9ng. M\u1ecdi thay \u0111\u1ed5i \u0111\u1ec1u ti\u1ec1m \u1ea9n r\u1ee7i ro cao.<\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">\u0110\u01b0\u1ee3c bao ph\u1ee7 b\u1edfi c\u00e1c b\u00e0i ki\u1ec3m th\u1eed t\u1ef1 \u0111\u1ed9ng (Unit, Integration, End-to-End Tests). Thay \u0111\u1ed5i an to\u00e0n h\u01a1n.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\"><strong>Kh\u1ea3 n\u0103ng thay \u0111\u1ed5i\/M\u1edf r\u1ed9ng<\/strong><\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">Kh\u00f3 thay \u0111\u1ed5i v\u00e0 m\u1edf r\u1ed9ng. Vi\u1ec7c th\u00eam t\u00ednh n\u0103ng m\u1edbi ho\u1eb7c s\u1eeda l\u1ed7i d\u1ec5 g\u00e2y ra bug \u1edf nh\u1eefng ph\u1ea7n kh\u00e1c.<\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">D\u1ec5 d\u00e0ng thay \u0111\u1ed5i v\u00e0 m\u1edf r\u1ed9ng. \u0110\u01b0\u1ee3c thi\u1ebft k\u1ebf \u0111\u1ec3 linh ho\u1ea1t, d\u1ec5 d\u00e0ng t\u00edch h\u1ee3p t\u00ednh n\u0103ng m\u1edbi.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\"><strong>\u0110\u1ed9 ph\u1ee9c t\u1ea1p<\/strong><\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">Th\u01b0\u1eddng r\u1ea5t ph\u1ee9c t\u1ea1p, r\u01b0\u1eddm r\u00e0, kh\u00f3 hi\u1ec3u. C\u00f3 th\u1ec3 ch\u1ee9a &#8220;Spaghetti Code&#8221; (m\u00e3 r\u1ed1i r\u1eafm, thi\u1ebfu c\u1ea5u tr\u00fac).<\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">S\u1ea1ch s\u1ebd, r\u00f5 r\u00e0ng, tu\u00e2n th\u1ee7 c\u00e1c nguy\u00ean t\u1eafc thi\u1ebft k\u1ebf. D\u1ec5 \u0111\u1ecdc v\u00e0 d\u1ec5 hi\u1ec3u b\u1edfi c\u00e1c l\u1eadp tr\u00ecnh vi\u00ean kh\u00e1c.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\"><strong>T\u00e0i li\u1ec7u<\/strong><\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">Thi\u1ebfu ho\u1eb7c kh\u00f4ng c\u00f3 t\u00e0i li\u1ec7u, ho\u1eb7c t\u00e0i li\u1ec7u \u0111\u00e3 l\u1ed7i th\u1eddi. G\u00e2y kh\u00f3 kh\u0103n trong vi\u1ec7c hi\u1ec3u logic nghi\u1ec7p v\u1ee5.<\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">C\u00f3 t\u00e0i li\u1ec7u \u0111\u1ea7y \u0111\u1ee7 v\u00e0 \u0111\u01b0\u1ee3c c\u1eadp nh\u1eadt th\u01b0\u1eddng xuy\u00ean. Gi\u00fap \u0111\u1ed9i ng\u0169 m\u1edbi d\u1ec5 d\u00e0ng ti\u1ebfp c\u1eadn.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\"><strong>C\u00f4ng ngh\u1ec7\/Th\u01b0 vi\u1ec7n<\/strong><\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">S\u1eed d\u1ee5ng c\u00f4ng ngh\u1ec7, th\u01b0 vi\u1ec7n, framework l\u1ed7i th\u1eddi. Kh\u00f3 t\u01b0\u01a1ng th\u00edch v\u1edbi c\u00e1c gi\u1ea3i ph\u00e1p hi\u1ec7n \u0111\u1ea1i.<\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">S\u1eed d\u1ee5ng c\u00f4ng ngh\u1ec7, th\u01b0 vi\u1ec7n, framework hi\u1ec7n h\u00e0nh. D\u1ec5 d\u00e0ng t\u00edch h\u1ee3p v\u00e0 n\u00e2ng c\u1ea5p.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\"><strong>Chi ph\u00ed<\/strong><\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">Chi ph\u00ed b\u1ea3o tr\u00ec, s\u1eeda l\u1ed7i v\u00e0 ph\u00e1t tri\u1ec3n cao. Do m\u1ea5t nhi\u1ec1u th\u1eddi gian \u0111\u1ec3 hi\u1ec3u v\u00e0 thay \u0111\u1ed5i.<\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">Chi ph\u00ed b\u1ea3o tr\u00ec, s\u1eeda l\u1ed7i v\u00e0 ph\u00e1t tri\u1ec3n th\u1ea5p h\u01a1n. Do t\u00ednh d\u1ec5 \u0111\u1ecdc v\u00e0 d\u1ec5 thay \u0111\u1ed5i.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\"><strong>R\u1ee7i ro<\/strong><\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">R\u1ee7i ro cao. D\u1ec5 ph\u00e1t sinh l\u1ed7i m\u1edbi, l\u1ed7 h\u1ed5ng b\u1ea3o m\u1eadt do thi\u1ebfu ki\u1ec3m so\u00e1t v\u00e0 thi\u1ebfu c\u1eadp nh\u1eadt.<\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">R\u1ee7i ro th\u1ea5p h\u01a1n. \u0110\u01b0\u1ee3c ki\u1ec3m so\u00e1t ch\u1eb7t ch\u1ebd th\u00f4ng qua test v\u00e0 quy tr\u00ecnh ph\u00e1t tri\u1ec3n.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\"><strong>Tinh th\u1ea7n l\u00e0m vi\u1ec7c<\/strong><\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">G\u00e2y ra s\u1ef1 n\u1ea3n l\u00f2ng, s\u1ee3 h\u00e3i cho l\u1eadp tr\u00ecnh vi\u00ean.<\/span><\/td>\n<td style=\"border: 1px solid #0D6EFD; padding: 10px;\"><span style=\"color: #000000;\">T\u1ea1o m\u00f4i tr\u01b0\u1eddng l\u00e0m vi\u1ec7c tho\u1ea3i m\u00e1i, hi\u1ec7u qu\u1ea3.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>S\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa Legacy Code v\u00e0 New Code kh\u00f4ng ch\u1ec9 mang t\u00ednh h\u1ecdc thu\u1eadt m\u00e0 c\u00f2n \u1ea3nh h\u01b0\u1edfng tr\u1ef1c ti\u1ebfp \u0111\u1ebfn hi\u1ec7u su\u1ea5t l\u00e0m vi\u1ec7c, chi ph\u00ed d\u1ef1 \u00e1n v\u00e0 kh\u1ea3 n\u0103ng c\u1ea1nh tranh c\u1ee7a doanh nghi\u1ec7p. L\u00e0m vi\u1ec7c v\u1edbi Legacy Code th\u01b0\u1eddng d\u1eabn \u0111\u1ebfn &#8220;n\u1ee3 k\u1ef9 thu\u1eadt&#8221; (Technical Debt) gia t\u0103ng, l\u00e0m ch\u1eadm t\u1ed1c \u0111\u1ed9 ph\u00e1t tri\u1ec3n v\u00e0 t\u0103ng r\u1ee7i ro.<\/p>\n<p>Ng\u01b0\u1ee3c l\u1ea1i, New Code v\u1edbi ch\u1ea5t l\u01b0\u1ee3ng cao gi\u00fap \u0111\u1ea9y nhanh ti\u1ebfn \u0111\u1ed9, gi\u1ea3m thi\u1ec3u l\u1ed7i v\u00e0 cho ph\u00e9p doanh nghi\u1ec7p nhanh ch\u00f3ng th\u00edch nghi v\u1edbi c\u00e1c y\u00eau c\u1ea7u thay \u0111\u1ed5i.<\/p>\n<p>Vi\u1ec7c hi\u1ec3u r\u00f5 s\u1ef1 kh\u00e1c bi\u1ec7t n\u00e0y l\u00e0 b\u01b0\u1edbc \u0111\u1ea7u ti\u00ean \u0111\u1ec3 c\u00e1c l\u1eadp tr\u00ecnh vi\u00ean v\u00e0 qu\u1ea3n l\u00fd d\u1ef1 \u00e1n c\u00f3 th\u1ec3 \u0111\u01b0a ra nh\u1eefng quy\u1ebft \u0111\u1ecbnh \u0111\u00fang \u0111\u1eafn, t\u1eeb vi\u1ec7c l\u1ef1a ch\u1ecdn chi\u1ebfn l\u01b0\u1ee3c refactor ph\u00f9 h\u1ee3p \u0111\u1ebfn vi\u1ec7c \u0111\u1ea7u t\u01b0 v\u00e0o c\u00e1c c\u00f4ng c\u1ee5 v\u00e0 quy tr\u00ecnh ph\u00e1t tri\u1ec3n hi\u1ec7n \u0111\u1ea1i.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cac-phuong-phap-tiep-can-xu-ly-Legacy-Code-hieu-qua\"><\/span>C\u00e1c ph\u01b0\u01a1ng ph\u00e1p ti\u1ebfp c\u1eadn &amp; x\u1eed l\u00fd Legacy Code hi\u1ec7u qu\u1ea3<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u1ec3 &#8220;thu\u1ea7n h\u00f3a&#8221; Legacy Code, ch\u00fang ta c\u1ea7n \u00e1p d\u1ee5ng c\u00e1c ph\u01b0\u01a1ng ph\u00e1p v\u00e0 chi\u1ebfn l\u01b0\u1ee3c c\u00f3 h\u1ec7 th\u1ed1ng. M\u1ee5c ti\u00eau kh\u00f4ng ph\u1ea3i l\u00fac n\u00e0o c\u0169ng l\u00e0 vi\u1ebft l\u1ea1i t\u1eeb \u0111\u1ea7u, m\u00e0 l\u00e0 c\u1ea3i thi\u1ec7n d\u1ea7n d\u1ea7n \u0111\u1ec3 t\u0103ng kh\u1ea3 n\u0103ng duy tr\u00ec v\u00e0 m\u1edf r\u1ed9ng.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Refactoring-Tai-cau-truc-ma-nguon\"><\/span>Refactoring (T\u00e1i c\u1ea5u tr\u00fac m\u00e3 ngu\u1ed3n)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Refactoring<\/strong> l\u00e0 qu\u00e1 tr\u00ecnh c\u1ea3i thi\u1ec7n c\u1ea5u tr\u00fac b\u00ean trong c\u1ee7a m\u00e3 ngu\u1ed3n m\u00e0 kh\u00f4ng thay \u0111\u1ed5i h\u00e0nh vi b\u00ean ngo\u00e0i c\u1ee7a n\u00f3. \u0110\u00e2y l\u00e0 m\u1ed9t trong nh\u1eefng k\u1ef9 thu\u1eadt quan tr\u1ecdng nh\u1ea5t khi l\u00e0m vi\u1ec7c v\u1edbi Legacy Code. M\u1ee5c \u0111\u00edch l\u00e0 l\u00e0m cho m\u00e3 ngu\u1ed3n d\u1ec5 \u0111\u1ecdc h\u01a1n, d\u1ec5 hi\u1ec3u h\u01a1n v\u00e0 d\u1ec5 b\u1ea3o tr\u00ec h\u01a1n.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Viet-kiem-thu-Unit-Test-cho-Legacy-Code\"><\/span>Vi\u1ebft ki\u1ec3m th\u1eed (Unit Test) cho Legacy Code<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Vi\u1ec7c th\u00eam c\u00e1c b\u00e0i ki\u1ec3m th\u1eed t\u1ef1 \u0111\u1ed9ng, \u0111\u1eb7c bi\u1ec7t l\u00e0 <strong>Unit Test<\/strong>, l\u00e0 b\u01b0\u1edbc \u0111i then ch\u1ed1t khi x\u1eed l\u00fd Legacy Code. N\u1ebfu kh\u00f4ng c\u00f3 test, m\u1ecdi thay \u0111\u1ed5i \u0111\u1ec1u l\u00e0 r\u1ee7i ro. C\u00e1c b\u00e0i ki\u1ec3m th\u1eed ho\u1ea1t \u0111\u1ed9ng nh\u01b0 m\u1ed9t &#8220;t\u1ea5m l\u01b0\u1edbi an to\u00e0n&#8221;, \u0111\u1ea3m b\u1ea3o r\u1eb1ng c\u00e1c thay \u0111\u1ed5i b\u1ea1n th\u1ef1c hi\u1ec7n kh\u00f4ng ph\u00e1 v\u1ee1 c\u00e1c ch\u1ee9c n\u0103ng hi\u1ec7n c\u00f3.<\/p>\n<p>Khi l\u00e0m vi\u1ec7c v\u1edbi Legacy Code, b\u1ea1n c\u00f3 th\u1ec3 b\u1eaft \u0111\u1ea7u b\u1eb1ng vi\u1ec7c vi\u1ebft &#8220;Characterization Tests&#8221; \u2013 c\u00e1c b\u00e0i ki\u1ec3m th\u1eed ghi l\u1ea1i h\u00e0nh vi hi\u1ec7n t\u1ea1i c\u1ee7a m\u00e3 ngu\u1ed3n. Sau \u0111\u00f3, khi b\u1ea1n \u0111\u00e3 c\u00f3 m\u1ed9t l\u1edbp b\u1ea3o v\u1ec7, b\u1ea1n c\u00f3 th\u1ec3 t\u1ef1 tin h\u01a1n \u0111\u1ec3 th\u1ef1c hi\u1ec7n refactor ho\u1eb7c th\u00eam t\u00ednh n\u0103ng m\u1edbi.<\/p>\n<figure id=\"attachment_30665\" aria-describedby=\"caption-attachment-30665\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Cac-phuong-phap-tiep-can-xu-ly-Legacy-Code-hieu-qua.jpg\" alt=\"C\u00e1c ph\u01b0\u01a1ng ph\u00e1p ti\u1ebfp c\u1eadn &amp; x\u1eed l\u00fd Legacy Code hi\u1ec7u qu\u1ea3\" width=\"800\" height=\"500\" class=\"size-full wp-image-30665\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Cac-phuong-phap-tiep-can-xu-ly-Legacy-Code-hieu-qua.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Cac-phuong-phap-tiep-can-xu-ly-Legacy-Code-hieu-qua-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Cac-phuong-phap-tiep-can-xu-ly-Legacy-Code-hieu-qua-768x480.jpg 768w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/06\/Cac-phuong-phap-tiep-can-xu-ly-Legacy-Code-hieu-qua-750x469.jpg 750w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-30665\" class=\"wp-caption-text\">C\u00e1c ph\u01b0\u01a1ng ph\u00e1p ti\u1ebfp c\u1eadn &amp; x\u1eed l\u00fd Legacy Code hi\u1ec7u qu\u1ea3<\/figcaption><\/figure>\n<h3><span class=\"ez-toc-section\" id=\"-Chien-luoc-%E2%80%9CStrangler-Fig-Pattern%E2%80%9D\"><\/span>\u00a0Chi\u1ebfn l\u01b0\u1ee3c &#8220;Strangler Fig Pattern&#8221;<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Strangler Fig Pattern<\/strong> l\u00e0 m\u1ed9t chi\u1ebfn l\u01b0\u1ee3c hi\u1ec7u qu\u1ea3 \u0111\u1ec3 t\u1eebng b\u01b0\u1edbc hi\u1ec7n \u0111\u1ea1i h\u00f3a m\u1ed9t h\u1ec7 th\u1ed1ng Legacy l\u1edbn. Thay v\u00ec c\u1ed1 g\u1eafng thay th\u1ebf to\u00e0n b\u1ed9 h\u1ec7 th\u1ed1ng c\u00f9ng l\u00fac (r\u1ea5t r\u1ee7i ro v\u00e0 t\u1ed1n k\u00e9m), b\u1ea1n s\u1ebd t\u1ea1o ra c\u00e1c d\u1ecbch v\u1ee5 ho\u1eb7c module m\u1edbi b\u00ean c\u1ea1nh h\u1ec7 th\u1ed1ng c\u0169. D\u1ea7n d\u1ea7n, b\u1ea1n &#8220;chuy\u1ec3n h\u01b0\u1edbng&#8221; l\u01b0u l\u01b0\u1ee3ng truy c\u1eadp t\u1eeb h\u1ec7 th\u1ed1ng c\u0169 sang c\u00e1c d\u1ecbch v\u1ee5 m\u1edbi, cho \u0111\u1ebfn khi ph\u1ea7n Legacy b\u1ecb &#8220;si\u1ebft ch\u1eb7t&#8221; v\u00e0 cu\u1ed1i c\u00f9ng \u0111\u01b0\u1ee3c lo\u1ea1i b\u1ecf.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Giai-quyet-%E2%80%9CCon-no-ky-thuat%E2%80%9D-Technical-Debt\"><\/span>Gi\u1ea3i quy\u1ebft &#8220;Con n\u1ee3 k\u1ef9 thu\u1eadt&#8221; (Technical Debt)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Con n\u1ee3 k\u1ef9 thu\u1eadt (Technical Debt)<\/strong> l\u00e0 m\u1ed9t thu\u1eadt ng\u1eef m\u00f4 t\u1ea3 chi ph\u00ed ph\u00e1t sinh trong t\u01b0\u01a1ng lai do c\u00e1c quy\u1ebft \u0111\u1ecbnh k\u1ef9 thu\u1eadt &#8220;nhanh ch\u00f3ng&#8221; ho\u1eb7c k\u00e9m ch\u1ea5t l\u01b0\u1ee3ng \u0111\u01b0\u1ee3c \u0111\u01b0a ra trong qu\u00e1 kh\u1ee9. Legacy Code th\u01b0\u1eddng l\u00e0 bi\u1ec3u hi\u1ec7n r\u00f5 r\u00e0ng nh\u1ea5t c\u1ee7a n\u1ee3 k\u1ef9 thu\u1eadt t\u00edch l\u0169y.<\/p>\n<p>\u0110\u1ec3 gi\u1ea3i quy\u1ebft n\u1ee3 k\u1ef9 thu\u1eadt, b\u1ea1n c\u1ea7n:<\/p>\n<ul>\n<li><strong>X\u00e1c \u0111\u1ecbnh v\u00e0 \u01b0u ti\u00ean:<\/strong> \u0110\u00e1nh gi\u00e1 m\u1ee9c \u0111\u1ed9 nghi\u00eam tr\u1ecdng c\u1ee7a t\u1eebng kho\u1ea3n n\u1ee3 k\u1ef9 thu\u1eadt v\u00e0 \u01b0u ti\u00ean gi\u1ea3i quy\u1ebft nh\u1eefng v\u1ea5n \u0111\u1ec1 c\u1ea5p b\u00e1ch nh\u1ea5t.<\/li>\n<li><strong>L\u1eadp k\u1ebf ho\u1ea1ch:<\/strong> \u0110\u01b0a vi\u1ec7c refactor ho\u1eb7c c\u1ea3i thi\u1ec7n ch\u1ea5t l\u01b0\u1ee3ng m\u00e3 ngu\u1ed3n v\u00e0o l\u1ed9 tr\u00ecnh ph\u00e1t tri\u1ec3n \u0111\u1ecbnh k\u1ef3.<\/li>\n<li><strong>Gi\u00e1o d\u1ee5c \u0111\u1ed9i ng\u0169:<\/strong> \u0110\u1ea3m b\u1ea3o m\u1ecdi th\u00e0nh vi\u00ean hi\u1ec3u v\u1ec1 t\u1ea7m quan tr\u1ecdng c\u1ee7a vi\u1ec7c duy tr\u00ec ch\u1ea5t l\u01b0\u1ee3ng m\u00e3 ngu\u1ed3n \u0111\u1ec3 tr\u00e1nh t\u1ea1o ra th\u00eam n\u1ee3 k\u1ef9 thu\u1eadt m\u1edbi.<\/li>\n<\/ul>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul><\/ul>\n<\/li>\n<\/ul>\n<p>B\u1eb1ng c\u00e1ch k\u1ebft h\u1ee3p c\u00e1c ph\u01b0\u01a1ng ph\u00e1p n\u00e0y, b\u1ea1n kh\u00f4ng ch\u1ec9 &#8220;ch\u1ebf ng\u1ef1&#8221; \u0111\u01b0\u1ee3c Legacy Code m\u00e0 c\u00f2n c\u1ea3i thi\u1ec7n \u0111\u00e1ng k\u1ec3 ch\u1ea5t l\u01b0\u1ee3ng v\u00e0 kh\u1ea3 n\u0103ng b\u1ea3o tr\u00ec c\u1ee7a to\u00e0n b\u1ed9 h\u1ec7 th\u1ed1ng ph\u1ea7n m\u1ec1m.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cac-cong-cu-hien-dai-ho-tro-Legacy-Code\"><\/span>C\u00e1c c\u00f4ng c\u1ee5 hi\u1ec7n \u0111\u1ea1i h\u1ed7 tr\u1ee3 Legacy Code<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Trong cu\u1ed9c chi\u1ebfn ch\u1ed1ng l\u1ea1i Legacy Code, c\u00e1c c\u00f4ng c\u1ee5 hi\u1ec7n \u0111\u1ea1i l\u00e0 \u0111\u1ed3ng minh \u0111\u1eafc l\u1ef1c. Ch\u00fang gi\u00fap t\u1ef1 \u0111\u1ed9ng h\u00f3a qu\u00e1 tr\u00ecnh ph\u00e2n t\u00edch, ki\u1ec3m th\u1eed v\u00e0 c\u1ea3i thi\u1ec7n m\u00e3 ngu\u1ed3n, gi\u1ea3m g\u00e1nh n\u1eb7ng cho l\u1eadp tr\u00ecnh vi\u00ean.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Cong-cu-phan-tich-ma-tinh-Static-Code-Analysis-Tools\"><\/span>C\u00f4ng c\u1ee5 ph\u00e2n t\u00edch m\u00e3 t\u0129nh (Static Code Analysis Tools)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>C\u00f4ng c\u1ee5 ph\u00e2n t\u00edch m\u00e3 t\u0129nh<\/strong> gi\u00fap ph\u00e1t hi\u1ec7n c\u00e1c l\u1ed7i ti\u1ec1m \u1ea9n, l\u1ed7 h\u1ed5ng b\u1ea3o m\u1eadt, vi ph\u1ea1m quy t\u1eafc l\u1eadp tr\u00ecnh v\u00e0 c\u00e1c v\u1ea5n \u0111\u1ec1 v\u1ec1 ch\u1ea5t l\u01b0\u1ee3ng m\u00e3 ngu\u1ed3n m\u00e0 kh\u00f4ng c\u1ea7n ch\u1ea1y ch\u01b0\u01a1ng tr\u00ecnh. Ch\u00fang qu\u00e9t m\u00e3 ngu\u1ed3n c\u1ee7a b\u1ea1n v\u00e0 b\u00e1o c\u00e1o c\u00e1c v\u1ea5n \u0111\u1ec1.<\/p>\n<p><strong>V\u00ed d\u1ee5:<\/strong><\/p>\n<ul>\n<li><strong>SonarQube:<\/strong> M\u1ed9t n\u1ec1n t\u1ea3ng to\u00e0n di\u1ec7n \u0111\u1ec3 li\u00ean t\u1ee5c ki\u1ec3m tra ch\u1ea5t l\u01b0\u1ee3ng m\u00e3 v\u00e0 b\u1ea3o m\u1eadt, h\u1ed7 tr\u1ee3 nhi\u1ec1u <a href=\"https:\/\/interdata.vn\/blog\/ngon-ngu-lap-trinh-la-gi\/\">ng\u00f4n ng\u1eef l\u1eadp tr\u00ecnh<\/a>. N\u00f3 cung c\u1ea5p c\u00e1c b\u00e1o c\u00e1o chi ti\u1ebft v\u00e0 c\u1ea3nh b\u00e1o v\u1ec1 &#8220;code smells&#8221; (m\u00e3 ngu\u1ed3n c\u00f3 v\u1ea5n \u0111\u1ec1 nh\u01b0ng ch\u01b0a ph\u1ea3i l\u1ed7i), bugs v\u00e0 l\u1ed7 h\u1ed5ng.<\/li>\n<li><strong>ESLint (cho <a href=\"https:\/\/interdata.vn\/blog\/javascript-la-gi\/\">JavaScript<\/a>), Checkstyle (cho <a href=\"https:\/\/interdata.vn\/blog\/ngon-ngu-lap-trinh-java\/\">Java<\/a>), Pylint (cho Python):<\/strong> C\u00e1c c\u00f4ng c\u1ee5 gi\u00fap th\u1ef1c thi c\u00e1c quy t\u1eafc l\u1eadp tr\u00ecnh, \u0111\u1ecbnh d\u1ea1ng m\u00e3 v\u00e0 ph\u00e1t hi\u1ec7n c\u00e1c v\u1ea5n \u0111\u1ec1 ng\u1eef ph\u00e1p, c\u00fa ph\u00e1p ph\u1ed5 bi\u1ebfn.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Khung-kiem-tra-tu-dong-Automated-Testing-Frameworks\"><\/span>Khung ki\u1ec3m tra t\u1ef1 \u0111\u1ed9ng (Automated Testing Frameworks)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u1ec3 t\u1ea1o ra c\u00e1c b\u00e0i ki\u1ec3m th\u1eed \u0111\u00e1ng tin c\u1eady cho Legacy Code, b\u1ea1n c\u1ea7n c\u00e1c <strong>khung ki\u1ec3m tra t\u1ef1 \u0111\u1ed9ng<\/strong>. Ch\u00fang cung c\u1ea5p c\u1ea5u tr\u00fac v\u00e0 c\u00e1c h\u00e0m ti\u1ec7n \u00edch \u0111\u1ec3 vi\u1ebft v\u00e0 ch\u1ea1y c\u00e1c b\u00e0i ki\u1ec3m th\u1eed unit, integration, v\u00e0 end-to-end.<\/p>\n<p><strong>V\u00ed d\u1ee5:<\/strong><\/p>\n<ul>\n<li><strong>JUnit (Java), NUnit (.NET), Jest (JavaScript), Pytest (Python), RSpec (Ruby):<\/strong> \u0110\u00e2y l\u00e0 nh\u1eefng framework ph\u1ed5 bi\u1ebfn cho Unit Testing, gi\u00fap l\u1eadp tr\u00ecnh vi\u00ean vi\u1ebft c\u00e1c b\u00e0i ki\u1ec3m th\u1eed nh\u1ecf, c\u00f4 l\u1eadp cho t\u1eebng \u0111\u01a1n v\u1ecb m\u00e3.<\/li>\n<li><strong>Selenium, Cypress (cho Web):<\/strong> C\u00e1c framework n\u00e0y gi\u00fap t\u1ef1 \u0111\u1ed9ng h\u00f3a ki\u1ec3m th\u1eed giao di\u1ec7n ng\u01b0\u1eddi d\u00f9ng (<a href=\"https:\/\/interdata.vn\/blog\/ui-la-gi\/\">UI<\/a>) v\u00e0 lu\u1ed3ng nghi\u1ec7p v\u1ee5 tr\u00ean tr\u00ecnh duy\u1ec7t.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Bo-cong-cu-va-nen-tang-di-chuyen-Migration-Toolkits-and-Platforms\"><\/span>B\u1ed9 c\u00f4ng c\u1ee5 v\u00e0 n\u1ec1n t\u1ea3ng di chuy\u1ec3n (Migration Toolkits and Platforms)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Khi quy\u1ebft \u0111\u1ecbnh di chuy\u1ec3n t\u1eeb h\u1ec7 th\u1ed1ng Legacy sang c\u00f4ng ngh\u1ec7 m\u1edbi ho\u1eb7c n\u1ec1n t\u1ea3ng \u0111\u00e1m m\u00e2y, c\u00e1c <strong>c\u00f4ng c\u1ee5 di chuy\u1ec3n<\/strong> c\u00f3 th\u1ec3 gi\u00fap <strong>gi\u1ea3m thi\u1ec3u r\u1ee7i ro v\u00e0 t\u0103ng t\u1ed1c qu\u00e1 tr\u00ecnh<\/strong>.<\/p>\n<p><strong>V\u00ed d\u1ee5:<\/strong><\/p>\n<ul>\n<li><strong>C\u00e1c d\u1ecbch v\u1ee5 di chuy\u1ec3n c\u01a1 s\u1edf d\u1eef li\u1ec7u c\u1ee7a AWS\/Azure\/GCP:<\/strong> C\u00e1c nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5 \u0111\u00e1m m\u00e2y th\u01b0\u1eddng cung c\u1ea5p c\u00e1c c\u00f4ng c\u1ee5 v\u00e0 d\u1ecbch v\u1ee5 chuy\u00ean bi\u1ec7t \u0111\u1ec3 di chuy\u1ec3n d\u1eef li\u1ec7u v\u00e0 c\u01a1 s\u1edf d\u1eef li\u1ec7u t\u1eeb m\u00f4i tr\u01b0\u1eddng on-premise ho\u1eb7c Legacy sang \u0111\u00e1m m\u00e2y.<\/li>\n<li><strong>C\u00e1c c\u00f4ng c\u1ee5 chuy\u1ec3n \u0111\u1ed5i ng\u00f4n ng\u1eef\/framework t\u1ef1 \u0111\u1ed9ng (t\u00f9y tr\u01b0\u1eddng h\u1ee3p c\u1ee5 th\u1ec3):<\/strong> M\u1ed9t s\u1ed1 c\u00f4ng c\u1ee5 c\u00f3 th\u1ec3 h\u1ed7 tr\u1ee3 t\u1ef1 \u0111\u1ed9ng chuy\u1ec3n \u0111\u1ed5i m\u1ed9t ph\u1ea7n m\u00e3 ngu\u1ed3n t\u1eeb ng\u00f4n ng\u1eef ho\u1eb7c framework c\u0169 sang m\u1edbi, m\u1eb7c d\u00f9 \u0111i\u1ec1u n\u00e0y th\u01b0\u1eddng \u0111\u00f2i h\u1ecfi s\u1ef1 can thi\u1ec7p th\u1ee7 c\u00f4ng \u0111\u00e1ng k\u1ec3.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Cong-cu-tao-tai-lieu-Documentation-Generation-Tools\"><\/span>C\u00f4ng c\u1ee5 t\u1ea1o t\u00e0i li\u1ec7u (Documentation Generation Tools)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>T\u1ea1o t\u00e0i li\u1ec7u t\u1ef1 \u0111\u1ed9ng<\/strong> gi\u00fap gi\u1ea3m b\u1edbt g\u00e1nh n\u1eb7ng cho l\u1eadp tr\u00ecnh vi\u00ean v\u00e0 \u0111\u1ea3m b\u1ea3o t\u00e0i li\u1ec7u lu\u00f4n \u0111\u01b0\u1ee3c c\u1eadp nh\u1eadt.<\/p>\n<p><strong>V\u00ed d\u1ee5: <\/strong><strong>Javadoc (Java), Doxygen (C++, Java, Python&#8230;), Sphinx (Python):<\/strong> C\u00e1c c\u00f4ng c\u1ee5 n\u00e0y c\u00f3 th\u1ec3 qu\u00e9t m\u00e3 ngu\u1ed3n v\u00e0 t\u1ea1o ra t\u00e0i li\u1ec7u API t\u1ef1 \u0111\u1ed9ng t\u1eeb c\u00e1c b\u00ecnh lu\u1eadn (comments) \u0111\u01b0\u1ee3c vi\u1ebft theo m\u1ed9t \u0111\u1ecbnh d\u1ea1ng c\u1ee5 th\u1ec3. \u0110i\u1ec1u n\u00e0y gi\u00fap c\u00e1c l\u1eadp tr\u00ecnh vi\u00ean kh\u00e1c d\u1ec5 d\u00e0ng hi\u1ec3u m\u1ee5c \u0111\u00edch v\u00e0 c\u00e1ch s\u1eed d\u1ee5ng c\u1ee7a c\u00e1c l\u1edbp, h\u00e0m.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Loi-khuyen-cho-lap-trinh-vien-khi-doi-mat-voi-Legacy-Code\"><\/span>L\u1eddi khuy\u00ean cho l\u1eadp tr\u00ecnh vi\u00ean khi \u0111\u1ed1i m\u1eb7t v\u1edbi Legacy Code<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>L\u00e0m vi\u1ec7c v\u1edbi Legacy Code c\u00f3 th\u1ec3 l\u00e0 m\u1ed9t th\u1eed th\u00e1ch l\u1edbn, nh\u01b0ng v\u1edbi t\u01b0 duy v\u00e0 ph\u01b0\u01a1ng ph\u00e1p \u0111\u00fang \u0111\u1eafn, b\u1ea1n ho\u00e0n to\u00e0n c\u00f3 th\u1ec3 v\u01b0\u1ee3t qua. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 nh\u1eefng l\u1eddi khuy\u00ean th\u1ef1c t\u1ebf:<\/p>\n<ul>\n<li><strong>\u0110\u1eebng s\u1ee3 h\u00e3i, h\u00e3y b\u1eaft \u0111\u1ea7u t\u1eeb nh\u1eefng thay \u0111\u1ed5i nh\u1ecf nh\u1ea5t: <\/strong>Thay v\u00ec c\u1ed1 g\u1eafng hi\u1ec3u to\u00e0n b\u1ed9 h\u1ec7 th\u1ed1ng ngay l\u1eadp t\u1ee9c, h\u00e3y t\u1eadp trung v\u00e0o ph\u1ea7n m\u00e3 ngu\u1ed3n b\u1ea1n c\u1ea7n thay \u0111\u1ed5i. Th\u1ef1c hi\u1ec7n nh\u1eefng thay \u0111\u1ed5i nh\u1ecf, c\u00f3 ki\u1ec3m so\u00e1t. M\u1ed7i thay \u0111\u1ed5i nh\u1ecf v\u00e0 th\u00e0nh c\u00f4ng s\u1ebd t\u0103ng s\u1ef1 t\u1ef1 tin c\u1ee7a b\u1ea1n.<\/li>\n<li><strong>Th\u00eam ki\u1ec3m th\u1eed tr\u01b0\u1edbc khi thay \u0111\u1ed5i: <\/strong>\u0110\u00e2y l\u00e0 nguy\u00ean t\u1eafc v\u00e0ng. Tr\u01b0\u1edbc khi ch\u1ec9nh s\u1eeda b\u1ea5t k\u1ef3 \u0111o\u1ea1n Legacy Code n\u00e0o, h\u00e3y c\u1ed1 g\u1eafng vi\u1ebft m\u1ed9t b\u00e0i ki\u1ec3m th\u1eed t\u1ef1 \u0111\u1ed9ng (unit test ho\u1eb7c integration test) \u0111\u1ec3 &#8220;bao ph\u1ee7&#8221; h\u00e0nh vi hi\u1ec7n t\u1ea1i c\u1ee7a n\u00f3. \u0110i\u1ec1u n\u00e0y t\u1ea1o ra m\u1ed9t &#8220;phao c\u1ee9u sinh&#8221; n\u1ebfu b\u1ea1n v\u00f4 t\u00ecnh g\u00e2y ra l\u1ed7i.<\/li>\n<li><strong>S\u1eed d\u1ee5ng k\u1ef9 thu\u1eadt &#8220;ghi ch\u00e9p&#8221; (scratchpad) khi \u0111\u1ecdc code: <\/strong>Khi c\u1ed1 g\u1eafng hi\u1ec3u m\u1ed9t \u0111o\u1ea1n code ph\u1ee9c t\u1ea1p, h\u00e3y t\u1ea1o m\u1ed9t t\u00e0i li\u1ec7u ho\u1eb7c ghi ch\u00fa ri\u00eang. Ghi l\u1ea1i c\u00e1c gi\u1ea3 \u0111\u1ecbnh c\u1ee7a b\u1ea1n, lu\u1ed3ng logic, v\u00e0 c\u00e1c \u0111i\u1ec3m c\u1ea7n l\u00e0m r\u00f5. B\u1ea1n c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng bi\u1ec3u \u0111\u1ed3, s\u01a1 \u0111\u1ed3 lu\u1ed3ng \u0111\u1ec3 tr\u1ef1c quan h\u00f3a.<\/li>\n<li><strong>H\u1ecdc c\u00e1ch refactor t\u1eebng b\u01b0\u1edbc nh\u1ecf: <\/strong>Refactoring kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t s\u1ef1 ki\u1ec7n l\u1edbn m\u00e0 l\u00e0 m\u1ed9t qu\u00e1 tr\u00ecnh li\u00ean t\u1ee5c. H\u1ecdc c\u00e1ch \u00e1p d\u1ee5ng c\u00e1c k\u1ef9 thu\u1eadt refactor nh\u1ecf (v\u00ed d\u1ee5: Extract Method, Rename Variable) \u0111\u1ec3 d\u1ea7n d\u1ea7n c\u1ea3i thi\u1ec7n ch\u1ea5t l\u01b0\u1ee3ng m\u00e3 ngu\u1ed3n m\u00e0 kh\u00f4ng l\u00e0m gi\u00e1n \u0111o\u1ea1n c\u00f4ng vi\u1ec7c.<\/li>\n<li><strong>Giao ti\u1ebfp v\u1edbi c\u00e1c th\u00e0nh vi\u00ean kh\u00e1c trong nh\u00f3m: <\/strong>\u0110\u1eebng ng\u1ea7n ng\u1ea1i h\u1ecfi nh\u1eefng ng\u01b0\u1eddi \u0111\u00e3 c\u00f3 kinh nghi\u1ec7m v\u1edbi m\u00e3 ngu\u1ed3n \u0111\u00f3. H\u1ecd c\u00f3 th\u1ec3 cung c\u1ea5p nh\u1eefng th\u00f4ng tin qu\u00fd gi\u00e1 v\u00e0 gi\u00fap b\u1ea1n hi\u1ec3u nhanh h\u01a1n. Chia s\u1ebb nh\u1eefng g\u00ec b\u1ea1n t\u00ecm th\u1ea5y c\u0169ng l\u00e0 c\u00e1ch t\u1ed1t \u0111\u1ec3 x\u00e2y d\u1ef1ng ki\u1ebfn th\u1ee9c chung.<\/li>\n<li><strong>\u0110\u1eebng c\u1ed1 g\u1eafng ho\u00e0n h\u1ea3o: <\/strong>M\u1ee5c ti\u00eau kh\u00f4ng ph\u1ea3i l\u00e0 bi\u1ebfn Legacy Code th\u00e0nh m\u1ed9t h\u1ec7 th\u1ed1ng ho\u00e0n h\u1ea3o ngay l\u1eadp t\u1ee9c. H\u00e3y t\u1eadp trung v\u00e0o vi\u1ec7c l\u00e0m cho n\u00f3 t\u1ed1t h\u01a1n m\u1ed9t ch\u00fat m\u1ed7i ng\u00e0y. M\u1ed7i c\u1ea3i ti\u1ebfn nh\u1ecf \u0111\u1ec1u c\u00f3 gi\u00e1 tr\u1ecb.<\/li>\n<li><strong>Hi\u1ec3u r\u00f5 b\u1ed1i c\u1ea3nh nghi\u1ec7p v\u1ee5: <\/strong>Th\u01b0\u1eddng th\u00ec Legacy Code ph\u1ea3n \u00e1nh m\u1ed9t quy tr\u00ecnh nghi\u1ec7p v\u1ee5 c\u0169 ho\u1eb7c m\u1ed9t gi\u1ea3i ph\u00e1p \u0111\u00e3 \u0111\u01b0\u1ee3c \u0111\u01b0a ra trong m\u1ed9t b\u1ed1i c\u1ea3nh nh\u1ea5t \u0111\u1ecbnh. Hi\u1ec3u r\u00f5 nghi\u1ec7p v\u1ee5 m\u00e0 code \u0111ang ph\u1ee5c v\u1ee5 s\u1ebd gi\u00fap b\u1ea1n hi\u1ec3u \u00fd \u0111\u1ed3 c\u1ee7a ng\u01b0\u1eddi vi\u1ebft ban \u0111\u1ea7u v\u00e0 \u0111\u01b0a ra nh\u1eefng thay \u0111\u1ed5i ph\u00f9 h\u1ee3p h\u01a1n.<\/li>\n<li><strong>S\u1eed d\u1ee5ng Version Control m\u1ed9t c\u00e1ch th\u00f4ng minh: <\/strong>\u0110\u1ea3m b\u1ea3o b\u1ea1n lu\u00f4n l\u00e0m vi\u1ec7c tr\u00ean m\u1ed9t nh\u00e1nh ri\u00eang v\u00e0 th\u01b0\u1eddng xuy\u00ean commit c\u00e1c thay \u0111\u1ed5i nh\u1ecf. \u0110i\u1ec1u n\u00e0y gi\u00fap b\u1ea1n d\u1ec5 d\u00e0ng quay l\u1ea1i c\u00e1c phi\u00ean b\u1ea3n tr\u01b0\u1edbc n\u1ebfu c\u00f3 v\u1ea5n \u0111\u1ec1 x\u1ea3y ra.<\/li>\n<\/ul>\n<p><strong>Legacy Code<\/strong> l\u00e0 m\u1ed9t ph\u1ea7n kh\u00f4ng th\u1ec3 tr\u00e1nh kh\u1ecfi trong h\u00e0nh tr\u00ecnh ph\u00e1t tri\u1ec3n ph\u1ea7n m\u1ec1m. Thay v\u00ec coi n\u00f3 l\u00e0 m\u1ed9t g\u00e1nh n\u1eb7ng kh\u00f4ng th\u1ec3 v\u01b0\u1ee3t qua, ch\u00fang ta c\u00f3 th\u1ec3 nh\u00ecn nh\u1eadn n\u00f3 nh\u01b0 m\u1ed9t c\u01a1 h\u1ed9i \u0111\u1ec3 r\u00e8n luy\u1ec7n k\u1ef9 n\u0103ng, \u00e1p d\u1ee5ng c\u00e1c ph\u01b0\u01a1ng ph\u00e1p v\u00e0 c\u00f4ng c\u1ee5 hi\u1ec7n \u0111\u1ea1i \u0111\u1ec3 bi\u1ebfn th\u00e1ch th\u1ee9c th\u00e0nh l\u1ee3i th\u1ebf.<\/p>\n<p>Vi\u1ec7c qu\u1ea3n l\u00fd v\u00e0 x\u1eed l\u00fd Legacy Code \u0111\u00f2i h\u1ecfi s\u1ef1 ki\u00ean nh\u1eabn, ki\u1ebfn th\u1ee9c v\u00e0 m\u1ed9t chi\u1ebfn l\u01b0\u1ee3c r\u00f5 r\u00e0ng. B\u1eb1ng c\u00e1ch \u00e1p d\u1ee5ng c\u00e1c ph\u01b0\u01a1ng ph\u00e1p nh\u01b0 refactoring, vi\u1ebft ki\u1ec3m th\u1eed, s\u1eed d\u1ee5ng c\u00e1c c\u00f4ng c\u1ee5 ph\u00e2n t\u00edch m\u00e3 t\u0129nh v\u00e0 di chuy\u1ec3n, c\u00f9ng v\u1edbi vi\u1ec7c duy tr\u00ec tinh th\u1ea7n h\u1ecdc h\u1ecfi, c\u00e1c l\u1eadp tr\u00ecnh vi\u00ean c\u00f3 th\u1ec3 d\u1ea7n d\u1ea7n c\u1ea3i thi\u1ec7n ch\u1ea5t l\u01b0\u1ee3ng m\u00e3 ngu\u1ed3n, gi\u1ea3m thi\u1ec3u r\u1ee7i ro v\u00e0 t\u0103ng c\u01b0\u1eddng hi\u1ec7u su\u1ea5t l\u00e0m vi\u1ec7c.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u0110\u00e3 bao gi\u1edd b\u1ea1n c\u1ea3m th\u1ea5y lo l\u1eafng khi ph\u1ea3i s\u1eeda m\u1ed9t l\u1ed7i nh\u1ecf trong m\u1ed9t h\u1ec7 th\u1ed1ng l\u1edbn v\u00e0 c\u0169 k\u1ef9 ch\u01b0a? Vi\u1ec7c hi\u1ec3u v\u00e0 l\u00e0m ch\u1ee7 Legacy Code kh\u00f4ng ch\u1ec9 l\u00e0 m\u1ed9t k\u1ef9 n\u0103ng sinh t\u1ed3n, m\u00e0 c\u00f2n l\u00e0 m\u1ed9t c\u01a1 h\u1ed9i l\u1edbn \u0111\u1ec3 b\u1ea1n kh\u1eb3ng \u0111\u1ecbnh gi\u00e1 tr\u1ecb chuy\u00ean m\u00f4n. B\u00e0i vi\u1ebft<\/p>\n","protected":false},"author":11,"featured_media":30666,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[140],"tags":[],"class_list":["post-30647","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-lap-trinh"],"_links":{"self":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/30647","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/comments?post=30647"}],"version-history":[{"count":2,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/30647\/revisions"}],"predecessor-version":[{"id":31651,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/30647\/revisions\/31651"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media\/30666"}],"wp:attachment":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media?parent=30647"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/categories?post=30647"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/tags?post=30647"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}