cache docgen results in between builds for faster startup times

Author: hipstersmoothie

package.json

@@ -26,12 +26,16 @@
   "dependencies": {
     "debug": "^4.1.1",
     "endent": "^2.0.1",
+    "find-cache-dir": "^3.3.1",
+    "flat-cache": "^3.0.4",
     "micromatch": "^4.0.2",
     "react-docgen-typescript": "^1.20.5",
     "tslib": "^2.0.0"
   },
   "devDependencies": {
     "@types/debug": "^4.1.5",
+    "@types/find-cache-dir": "^3.2.0",
+    "@types/flat-cache": "^2.0.0",
     "@types/jest": "^26.0.16",
     "@types/micromatch": "^4.0.1",
     "@types/node": "^14.0.12",

src/plugin.ts

@@ -1,16 +1,25 @@
+/* eslint-disable no-param-reassign, no-underscore-dangle */
+
 import path from "path";
 import createDebug from "debug";
 import * as webpack from "webpack";
 import ts from "typescript";
 import * as docGen from "react-docgen-typescript";
 import { matcher } from "micromatch";
+import findCacheDir from "find-cache-dir";
+import flatCache from "flat-cache";
+import crypto from "crypto";
 
 import { generateDocgenCodeBlock } from "./generateDocgenCodeBlock";
 
 const debugExclude = createDebug("docgen:exclude");
 const debugInclude = createDebug("docgen:include");
 const debugDocs = createDebug("docgen:docs");
 
+const cacheId = "ts-docgen";
+const cacheDir = findCacheDir({ name: cacheId });
+const cache = flatCache.load(cacheId, cacheDir);
+
 interface TypescriptOptions {
   /**
    * Specify the location of the tsconfig.json to use. Can not be used with
@@ -87,6 +96,18 @@ function processModule(
     return;
   }
 
+  const hash = crypto
+    .createHash("sha1")
+    .update(webpackModule._source._value)
+    .digest("hex");
+  const cached = cache.getKey(hash);
+
+  if (cached) {
+    debugInclude(`Got cached docgen for "${webpackModule.request}"`);
+    webpackModule._source._value = cached;
+    return;
+  }
+
   const componentDocs = parser.parseWithProgramProvider(
     webpackModule.userRequest,
     () => tsProgram
@@ -105,11 +126,11 @@ function processModule(
 
   debugDocs(docs);
 
-  // eslint-disable-next-line no-underscore-dangle
-  let source = webpackModule._source._value;
-  source += `\n${docs}\n`;
-  // eslint-disable-next-line no-underscore-dangle, no-param-reassign
-  webpackModule._source._value = source;
+  let sourceWithDocs = webpackModule._source._value;
+  sourceWithDocs += `\n${docs}\n`;
+  webpackModule._source._value = sourceWithDocs;
+
+  cache.setKey(hash, sourceWithDocs);
 }
 
 /** Get the contents of the tsconfig in the system */
@@ -231,6 +252,8 @@ export default class DocgenPlugin {
             typePropName,
           })
         );
+
+        cache.save();
       });
     });
   }

yarn.lock

@@ -862,6 +862,16 @@
   resolved "https://registry.yarnpkg.com/@types/debug/-/debug-4.1.5.tgz#b14efa8852b7768d898906613c23f688713e02cd"
   integrity sha512-Q1y515GcOdTHgagaVFhHnIFQ38ygs/kmxdNpvpou+raI9UO3YZcHDngBSYKQklcKlvA7iuQlmIKbzvmxcOE9CQ==
 
+"@types/find-cache-dir@^3.2.0":
+  version "3.2.0"
+  resolved "https://registry.yarnpkg.com/@types/find-cache-dir/-/find-cache-dir-3.2.0.tgz#eaaf331699dccf52c47926e4d4f8f3ed8db33f3c"
+  integrity sha512-+JeT9qb2Jwzw72WdjU+TSvD5O1QRPWCeRpDJV+guiIq+2hwR0DFGw+nZNbTFjMIVe6Bf4GgAKeB/6Ytx6+MbeQ==
+
+"@types/flat-cache@^2.0.0":
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/@types/flat-cache/-/flat-cache-2.0.0.tgz#64e5d3b426c392b603a208a55bdcc7d920ce6e57"
+  integrity sha512-fHeEsm9hvmZ+QHpw6Fkvf19KIhuqnYLU6vtWLjd5BsMd/qVi7iTkMioDZl0mQmfNRA1A6NwvhrSRNr9hGYZGww==
+
 "@types/graceful-fs@^4.1.2":
   version "4.1.4"
   resolved "https://registry.yarnpkg.com/@types/graceful-fs/-/graceful-fs-4.1.4.tgz#4ff9f641a7c6d1a3508ff88bc3141b152772e753"
@@ -1753,6 +1763,11 @@ comment-parser@^0.7.4:
   resolved "https://registry.yarnpkg.com/comment-parser/-/comment-parser-0.7.5.tgz#06db157a3b34addf8502393743e41897e2c73059"
   integrity sha512-iH9YA35ccw94nx5244GVkpyC9eVTsL71jZz6iz5w6RIf79JLF2AsXHXq9p6Oaohyl3sx5qSMnGsWUDFIAfWL4w==
 
+commondir@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/commondir/-/commondir-1.0.1.tgz#ddd800da0c66127393cca5950ea968a3aaf1253b"
+  integrity sha1-3dgA2gxmEnOTzKWVDqloo6rxJTs=
+
 component-emitter@^1.2.1:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/component-emitter/-/component-emitter-1.3.0.tgz#16e4070fba8ae29b679f2215853ee181ab2eabc0"
@@ -2619,6 +2634,15 @@ fill-range@^7.0.1:
   dependencies:
     to-regex-range "^5.0.1"
 
+find-cache-dir@^3.3.1:
+  version "3.3.1"
+  resolved "https://registry.yarnpkg.com/find-cache-dir/-/find-cache-dir-3.3.1.tgz#89b33fad4a4670daa94f855f7fbe31d6d84fe880"
+  integrity sha512-t2GDMt3oGC/v+BMwzmllWDuJF/xcDtE5j/fCGbqDD7OLuJkj0cfh1YSA5VKPvwMeLFLNDBkwOKZ2X85jGLVftQ==
+  dependencies:
+    commondir "^1.0.1"
+    make-dir "^3.0.2"
+    pkg-dir "^4.1.0"
+
 find-replace@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/find-replace/-/find-replace-3.0.0.tgz#3e7e23d3b05167a76f770c9fbd5258b0def68c38"
@@ -2650,11 +2674,24 @@ flat-cache@^2.0.1:
     rimraf "2.6.3"
     write "1.0.3"
 
+flat-cache@^3.0.4:
+  version "3.0.4"
+  resolved "https://registry.yarnpkg.com/flat-cache/-/flat-cache-3.0.4.tgz#61b0338302b2fe9f957dcc32fc2a87f1c3048b11"
+  integrity sha512-dm9s5Pw7Jc0GvMYbshN6zchCA9RgQlzzEZX3vylR9IqFfS8XciblUXOKfW6SiuJ0e13eDYZoZV5wdrev7P3Nwg==
+  dependencies:
+    flatted "^3.1.0"
+    rimraf "^3.0.2"
+
 flatted@^2.0.0:
   version "2.0.2"
   resolved "https://registry.yarnpkg.com/flatted/-/flatted-2.0.2.tgz#4575b21e2bcee7434aa9be662f4b7b5f9c2b5138"
   integrity sha512-r5wGx7YeOwNWNlCA0wQ86zKyDLMQr+/RB8xy74M4hTphfmjlijTSSXGuH8rnvKZnfT9i+75zmd8jcKdMR4O6jA==
 
+flatted@^3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/flatted/-/flatted-3.1.0.tgz#a5d06b4a8b01e3a63771daa5cb7a1903e2e57067"
+  integrity sha512-tW+UkmtNg/jv9CSofAKvgVcO7c2URjhTdW1ZTkcAritblu8tajiYy7YisnIflEwtKssCtOxpnBRoCB7iap0/TA==
+
 for-in@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/for-in/-/for-in-1.0.2.tgz#81068d295a8142ec0ac726c6e2200c30fb6d5e80"
@@ -4017,7 +4054,7 @@ macos-release@^2.2.0:
   resolved "https://registry.yarnpkg.com/macos-release/-/macos-release-2.3.0.tgz#eb1930b036c0800adebccd5f17bc4c12de8bb71f"
   integrity sha512-OHhSbtcviqMPt7yfw5ef5aghS2jzFVKEFyCJndQt2YpSQ9qRVSEv2axSJI1paVThEu+FFGs584h/1YhxjVqajA==
 
-make-dir@^3.0.0:
+make-dir@^3.0.0, make-dir@^3.0.2:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/make-dir/-/make-dir-3.1.0.tgz#415e967046b3a7f1d185277d84aa58203726a13f"
   integrity sha512-g3FeP20LNwhALb/6Cz6Dd4F2ngze0jz7tbzrD2wAV+o9FeNHe4rL+yK2md0J/fiSf1sa1ADhXqi5+oVwOM/eGw==
@@ -4616,7 +4653,7 @@ pkg-dir@^2.0.0:
   dependencies:
     find-up "^2.1.0"
 
-pkg-dir@^4.2.0:
+pkg-dir@^4.1.0, pkg-dir@^4.2.0:
   version "4.2.0"
   resolved "https://registry.yarnpkg.com/pkg-dir/-/pkg-dir-4.2.0.tgz#f099133df7ede422e81d1d8448270eeb3e4261f3"
   integrity sha512-HRDzbaKjC+AOWVXxAU/x54COGeIv9eb+6CkDSQoNTt4XyWoIJvuPsXizxu/Fr23EiekbtZwmh1IcIG/l/a10GQ==
@@ -4936,7 +4973,7 @@ rimraf@2.6.3:
   dependencies:
     glob "^7.1.3"
 
-rimraf@^3.0.0:
+rimraf@^3.0.0, rimraf@^3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/rimraf/-/rimraf-3.0.2.tgz#f1a5402ba6220ad52cc1282bac1ae3aa49fd061a"
   integrity sha512-JZkJMZkAGFFPP2YqXZXPbMlMBgsxzE8ILs4lMIX/2o0L9UBw9O/Y3o6wFw/i9YLapcUJWwqbi3kdxIPdC62TIA==