Expose watcher ignore and watcher backend options (#9547)

Author: Nikola-3

packages/core/core/src/RequestTracker.js

@@ -1289,17 +1289,24 @@ export default class RequestTracker {
   }
 }
 
-export function getWatcherOptions(options: ParcelOptions): WatcherOptions {
-  let vcsDirs = ['.git', '.hg'].map(dir => path.join(options.projectRoot, dir));
-  let ignore = [options.cacheDir, ...vcsDirs];
-  return {ignore};
+export function getWatcherOptions({
+  watchIgnore = [],
+  cacheDir,
+  projectRoot,
+  watchBackend,
+}: ParcelOptions): WatcherOptions {
+  const vcsDirs = ['.git', '.hg'];
+  const uniqueDirs = [...new Set([...watchIgnore, ...vcsDirs, cacheDir])];
+  const ignore = uniqueDirs.map(dir => path.join(projectRoot, dir));
+
+  return {ignore, backend: watchBackend};
 }
 
 function getCacheKey(options) {
   return hashString(
     `${PARCEL_VERSION}:${JSON.stringify(options.entries)}:${options.mode}:${
       options.shouldBuildLazily ? 'lazy' : 'eager'
-    }`,
+    }:${options.watchBackend ?? ''}`,
   );
 }
 

packages/core/core/src/resolveOptions.js

@@ -191,6 +191,8 @@ export default async function resolveOptions(
     shouldTrace: initialOptions.shouldTrace ?? false,
     cacheDir,
     watchDir,
+    watchBackend: initialOptions.watchBackend,
+    watchIgnore: initialOptions.watchIgnore,
     entries: entries.map(e => toProjectPath(projectRoot, e)),
     targets: initialOptions.targets,
     logLevel: initialOptions.logLevel ?? 'info',

packages/core/core/src/types.js

@@ -33,6 +33,7 @@ import type {PackageManager} from '@parcel/package-manager';
 import type {ProjectPath} from './projectPath';
 import type {EventType} from '@parcel/watcher';
 import type {FeatureFlags} from '@parcel/feature-flags';
+import type {BackendType} from '@parcel/watcher';
 
 export type ParcelPluginNode = {|
   packageName: PackageName,
@@ -266,16 +267,19 @@ export type DevDepRequest = {|
   |}>,
 |};
 
+declare type GlobPattern = string;
+
 export type ParcelOptions = {|
   entries: Array<ProjectPath>,
   config?: DependencySpecifier,
   defaultConfig?: DependencySpecifier,
   env: EnvMap,
   targets: ?(Array<string> | {+[string]: TargetDescriptor, ...}),
-
   shouldDisableCache: boolean,
   cacheDir: FilePath,
   watchDir: FilePath,
+  watchIgnore?: Array<FilePath | GlobPattern>,
+  watchBackend?: BackendType,
   mode: BuildMode,
   hmrOptions: ?HMROptions,
   shouldContentHash: boolean,

packages/core/core/test/test-utils.js

@@ -18,6 +18,8 @@ cache.ensure();
 export const DEFAULT_OPTIONS: ParcelOptions = {
   cacheDir: path.join(__dirname, '.parcel-cache'),
   watchDir: __dirname,
+  watchIgnore: undefined,
+  watchBackend: undefined,
   entries: [],
   logLevel: 'info',
   targets: undefined,

packages/core/parcel/src/cli.js

@@ -66,16 +66,46 @@ process.on('unhandledRejection', handleUncaughtException);
 program.storeOptionsAsProperties();
 program.version(version);
 
+// Only display choices available to callers OS
+let watcherBackendChoices = ['brute-force'];
+switch (process.platform) {
+  case 'darwin': {
+    watcherBackendChoices.push('watchman', 'fs-events');
+    break;
+  }
+  case 'linux': {
+    watcherBackendChoices.push('watchman', 'inotify');
+    break;
+  }
+  case 'win32': {
+    watcherBackendChoices.push('watchman', 'windows');
+    break;
+  }
+  case 'freebsd' || 'openbsd': {
+    watcherBackendChoices.push('watchman');
+    break;
+  }
+  default:
+    break;
+}
+
 // --no-cache, --cache-dir, --no-source-maps, --no-autoinstall, --global?, --public-url, --log-level
 // --no-content-hash, --experimental-scope-hoisting, --detailed-report
-
 const commonOptions = {
   '--no-cache': 'disable the filesystem cache',
   '--config <path>':
     'specify which config to use. can be a path or a package name',
   '--cache-dir <path>': 'set the cache directory. defaults to ".parcel-cache"',
   '--watch-dir <path>':
     'set the root watch directory. defaults to nearest lockfile or source control dir.',
+  '--watch-ignore [path]': [
+    `list of directories watcher should not be tracking for changes. defaults to ['.git', '.hg']`,
+    dirs => dirs.split(','),
+  ],
+  '--watch-backend': new commander.Option(
+    '--watch-backend <name>',
+    'set watcher backend',
+  ).choices(watcherBackendChoices),
   '--no-source-maps': 'disable sourcemaps',
   '--target [name]': [
     'only build given target(s)',
@@ -497,10 +527,13 @@ async function normalizeOptions(
     if (typeof input !== 'string') return [];
     return input.split(',').map(value => value.trim());
   };
+
   return {
     shouldDisableCache: command.cache === false,
     cacheDir: command.cacheDir,
     watchDir: command.watchDir,
+    watchBackend: command.watchBackend,
+    watchIgnore: command.watchIgnore,
     config: command.config,
     mode,
     hmrOptions,

packages/core/types/index.js

@@ -14,8 +14,8 @@ import type {Cache} from '@parcel/cache';
 
 import type {AST as _AST, ConfigResult as _ConfigResult} from './unsafe';
 import type {TraceMeasurement} from '@parcel/profiler';
-import type {EventType} from '@parcel/watcher';
 import type {FeatureFlags} from '@parcel/feature-flags';
+import type {EventType, BackendType} from '@parcel/watcher';
 
 /** Plugin-specific AST, <code>any</code> */
 export type AST = _AST;
@@ -286,6 +286,8 @@ export type DetailedReportOptions = {|
   assetsPerBundle?: number,
 |};
 
+declare type GlobPattern = string;
+
 export type InitialParcelOptions = {|
   +entries?: FilePath | Array<FilePath>,
   +config?: DependencySpecifier,
@@ -296,6 +298,8 @@ export type InitialParcelOptions = {|
   +shouldDisableCache?: boolean,
   +cacheDir?: FilePath,
   +watchDir?: FilePath,
+  +watchBackend?: BackendType,
+  +watchIgnore?: Array<FilePath | GlobPattern>,
   +mode?: BuildMode,
   +hmrOptions?: ?HMROptions,
   +shouldContentHash?: boolean,