feat: change start hook to AsyncSeriesWaterfallHook (#425)

Adds possibility to delay the start of the plugin by tapping into the
start hook.

BREAKING CHANGE: 🧨 start hook changed from SyncWaterfallHook to AsyncSeriesWaterfallHook

✅ Closes: #424

Author: piotr-oles

README.md

@@ -178,7 +178,7 @@ Options for the ESLint linter (`eslint` option object).
 
 | Name                 | Type                   | Default value             | Description |
 | -------------------- | ---------------------- | ------------------------- | ----------- |
-| `enabled`            | `boolean`              | `true`                    | If `true`, it enables ESLint linter. |
+| `enabled`            | `boolean`              | `false`                   | If `true`, it enables ESLint linter. |
 | `files`              | `string` or `string[]` | This value is required    | One or more [glob patterns](https://en.wikipedia.org/wiki/Glob_(programming)) to the files that should be linted. Works the same as the `eslint` command. |
 | `memoryLimit`        | `number`               | `2048`                    | Memory limit for the linter process in MB. If the process exits with the allocation failed error, try to increase this number. |
 | `options`            | `object`               | `{}`                      | [Options](https://eslint.org/docs/developer-guide/nodejs-api#cliengine) that can be used to initialize ESLint. |
@@ -316,13 +316,13 @@ If you use **TypeScript >=3.8.0**, you can fix it by passing `"importsNotUsedAsV
 
 This plugin provides some custom webpack hooks:
 
-| Hook key   | Type                | Params                | Description |
-| ---------- | ------------------- | --------------------- | ----------- |
-| `start`    | `SyncWaterfallHook` | `change, compilation` | Starts issues checking for a compilation. It's a waterfall hook, so you can modify the list of changed and removed files. |
-| `waiting`  | `SyncHook`          | `compilation`         | Waiting for the issues checking. |
-| `canceled` | `SyncHook`          | `compilation`         | Issues checking for the compilation has been canceled. |
-| `error`    | `SyncHook`          | `compilation`         | An error occurred during issues checking. |
-| `issues`   | `SyncWaterfallHook` | `issues, compilation` | Issues have been received and will be reported. It's a waterfall hook, so you can modify the list of received issues. |
+| Hook key   | Type                       | Params                | Description |
+| ---------- | -------------------------- | --------------------- | ----------- |
+| `start`    | `AsyncSeriesWaterfallHook` | `change, compilation` | Starts issues checking for a compilation. It's an async waterfall hook, so you can modify the list of changed and removed files or delay the start of the service. |
+| `waiting`  | `SyncHook`                 | `compilation`         | Waiting for the issues checking. |
+| `canceled` | `SyncHook`                 | `compilation`         | Issues checking for the compilation has been canceled. |
+| `error`    | `SyncHook`                 | `compilation`         | An error occurred during issues checking. |
+| `issues`   | `SyncWaterfallHook`        | `issues, compilation` | Issues have been received and will be reported. It's a waterfall hook, so you can modify the list of received issues. |
 
 To access plugin hooks and tap into the event, we need to use the `getCompilerHooks` static method.
 When we call this method with a [webpack compiler instance](https://webpack.js.org/api/node/), it returns the object with

src/hooks/pluginHooks.ts

@@ -1,5 +1,5 @@
 import * as webpack from 'webpack';
-import { SyncHook, SyncWaterfallHook } from 'tapable';
+import { SyncHook, SyncWaterfallHook, AsyncSeriesWaterfallHook } from 'tapable';
 import { FilesChange } from '../reporter';
 import { Issue } from '../issue';
 
@@ -10,7 +10,7 @@ const compilerHookMap = new WeakMap<
 
 function createForkTsCheckerWebpackPluginHooks() {
   return {
-    start: new SyncWaterfallHook<FilesChange, webpack.compilation.Compilation>([
+    start: new AsyncSeriesWaterfallHook<FilesChange, webpack.compilation.Compilation>([
       'change',
       'compilation',
     ]),
@@ -30,7 +30,7 @@ function forwardForkTsCheckerWebpackPluginHooks(
   source: ForkTsCheckerWebpackPluginHooks,
   target: ForkTsCheckerWebpackPluginHooks
 ) {
-  source.start.tap('ForkTsCheckerWebpackPlugin', target.start.call);
+  source.start.tapPromise('ForkTsCheckerWebpackPlugin', target.start.promise);
   source.waiting.tap('ForkTsCheckerWebpackPlugin', target.waiting.call);
   source.canceled.tap('ForkTsCheckerWebpackPlugin', target.canceled.call);
   source.error.tap('ForkTsCheckerWebpackPlugin', target.error.call);

src/hooks/tapStartToConnectAndRunReporter.ts

@@ -61,20 +61,24 @@ function tapStartToConnectAndRunReporter(
       configuration.logger.infrastructure.info('Calling reporter service for single check.');
     }
 
-    change = hooks.start.call(change, compilation);
+    state.report = new Promise(async (resolve) => {
+      change = await hooks.start.promise(change, compilation);
 
-    state.report = reporter
-      .connect()
-      .then(() => reporter.getReport(change))
-      .catch((error) => {
+      try {
+        await reporter.connect();
+        const report = await reporter.getReport(change);
+
+        resolve(report);
+      } catch (error) {
         if (error instanceof OperationCanceledError) {
           hooks.canceled.call(compilation);
         } else {
           hooks.error.call(error, compilation);
         }
 
-        return undefined;
-      });
+        resolve(undefined);
+      }
+    });
   });
 }