T-345 use loadconfig for posthtml (#4752)

* use new config functions for posthtml

* remove getconfig

* fix tests

* make . in canonical optional although I dont know how this test ever could fail

* cleanup

Author: DeMoorJasper

packages/core/core/src/Transformation.js

@@ -535,18 +535,6 @@ async function runTransformer(
     ).filePath;
   };
 
-  // Load config for the transformer.
-  let config = preloadedConfig;
-  if (transformer.getConfig) {
-    // TODO: deprecate getConfig
-    config = await transformer.getConfig({
-      asset: new MutableAsset(asset),
-      options: pipeline.pluginOptions,
-      resolve,
-      logger,
-    });
-  }
-
   // If an ast exists on the asset, but we cannot reuse it,
   // use the previous transform to generate code that we can re-parse.
   if (
@@ -565,6 +553,9 @@ async function runTransformer(
     asset.mapBuffer = output.map?.toBuffer();
   }
 
+  // Load config for the transformer.
+  let config = preloadedConfig;
+
   // Parse if there is no AST available from a previous transform.
   if (!asset.ast && transformer.parse) {
     let ast = await transformer.parse({

packages/core/integration-tests/test/html.js

@@ -110,7 +110,7 @@ describe('html', function() {
       'utf8',
     );
 
-    assert(/<link rel="canonical" href="\/index.html">/.test(html));
+    assert(/<link rel="canonical" href="\.?\/index.html">/.test(html));
   });
 
   it('should support meta tag with none content', async function() {

packages/core/integration-tests/test/pug.js

@@ -51,7 +51,7 @@ describe('pug', function() {
         name: 'index.html',
         assets: ['index.pug'],
         includedFiles: {
-          'index.pug': ['package.json', 'base.pug', 'other.pug', 'nested.pug'],
+          'index.pug': ['base.pug', 'other.pug', 'nested.pug'],
         },
       },
     ]);

packages/core/parcel/README.md

@@ -1390,11 +1390,6 @@ asset graph. They mostly call out to different compilers and preprocessors.
 import {Transform} from '@parcel/plugin';
 
 export default new Transform({
-  async getConfig({asset}) {
-    // ...
-    return config;
-  },
-
   async parse({asset}) {
     // ...
     return ast;

packages/core/types/index.js

@@ -504,13 +504,6 @@ export type MultiThreadValidator = {|
 export type Validator = DedicatedThreadValidator | MultiThreadValidator;
 
 export type Transformer = {|
-  // TODO: deprecate getConfig
-  getConfig?: ({|
-    asset: MutableAsset,
-    resolve: ResolveFn,
-    options: PluginOptions,
-    logger: PluginLogger,
-  |}) => Async<ConfigResult | void>,
   loadConfig?: ({|
     config: Config,
     options: PluginOptions,

packages/transformers/posthtml/src/PostHTMLTransformer.js

@@ -2,6 +2,7 @@
 
 import {Transformer} from '@parcel/plugin';
 
+import path from 'path';
 import posthtml from 'posthtml';
 import parse from 'posthtml-parser';
 import render from 'posthtml-render';
@@ -10,22 +11,38 @@ import semver from 'semver';
 import loadPlugins from './loadPlugins';
 
 export default new Transformer({
-  async getConfig({asset, options}) {
-    let config = await asset.getConfig(
+  async loadConfig({config}) {
+    let configFile = await config.getConfig(
       ['.posthtmlrc', '.posthtmlrc.js', 'posthtml.config.js'],
       {
         packageKey: 'posthtml',
       },
     );
 
-    config = config || {};
+    if (configFile) {
+      let isJavascript = path.extname(configFile.filePath) === '.js';
+      if (isJavascript) {
+        config.shouldInvalidateOnStartup();
+        config.shouldReload();
+      }
 
-    // load plugins
-    config.plugins = await loadPlugins(config.plugins, asset.filePath, options);
+      // tells posthtml that we have already called parse
+      configFile.contents.skipParse = true;
+
+      config.setResult({
+        contents: configFile.contents,
+        isSerialisable: !isJavascript,
+      });
+    }
+  },
+
+  preSerializeConfig({config}) {
+    if (!config.result) return;
 
-    // tells posthtml that we have already called parse
-    config.skipParse = true;
-    return config;
+    // Ensure we dont try to serialise functions
+    if (!config.result.isSerialisable) {
+      config.result.contents = {};
+    }
   },
 
   canReuseAST({ast}) {
@@ -47,13 +64,23 @@ export default new Transformer({
     };
   },
 
-  async transform({asset, config}) {
+  async transform({asset, config, options}) {
     if (!config) {
       return [asset];
     }
 
+    // load plugins
+    const plugins = await loadPlugins(
+      config.contents.plugins,
+      asset.filePath,
+      options,
+    );
+
     let ast = nullthrows(await asset.getAST());
-    let res = await posthtml(config.plugins).process(ast.program, config);
+    let res = await posthtml(plugins).process(ast.program, {
+      ...config.contents,
+      plugins,
+    });
 
     if (res.messages) {
       await Promise.all(