feat(typescript-estree): add flag EXPERIMENTAL_useSourceOfProjectReferenceRedirect

.eslintrc.js

@@ -26,6 +26,7 @@ module.exports = {
     ],
     tsconfigRootDir: __dirname,
     warnOnUnsupportedTypeScriptVersion: false,
+    EXPERIMENTAL_useSourceOfProjectReferenceRedirect: true,
   },
   rules: {
     //

packages/eslint-plugin-internal/tsconfig.json

@@ -4,5 +4,6 @@
     "composite": false,
     "rootDir": "."
   },
-  "include": ["src", "typings", "tests"]
+  "include": ["src", "typings", "tests"],
+  "references": [{ "path": "../experimental-utils/tsconfig.build.json" }]
 }

packages/eslint-plugin-tslint/tsconfig.build.json

@@ -6,9 +6,5 @@
     "resolveJsonModule": true
   },
   "include": ["src"],
-  "references": [
-    { "path": "../experimental-utils/tsconfig.build.json" },
-    { "path": "../parser/tsconfig.build.json" },
-    { "path": "../typescript-estree/tsconfig.build.json" }
-  ]
+  "references": [{ "path": "../experimental-utils/tsconfig.build.json" }]
 }

packages/eslint-plugin-tslint/tsconfig.json

@@ -5,5 +5,6 @@
     "rootDir": "."
   },
   "include": ["src", "tests"],
-  "exclude": ["tests/test-project", "tests/test-tslint-rules-directory"]
+  "exclude": ["tests/test-project", "tests/test-tslint-rules-directory"],
+  "references": [{ "path": "../experimental-utils/tsconfig.build.json" }]
 }

packages/eslint-plugin/tsconfig.build.json

@@ -12,7 +12,6 @@
   "references": [
     { "path": "../experimental-utils/tsconfig.build.json" },
     { "path": "../parser/tsconfig.build.json" },
-    { "path": "../scope-manager/tsconfig.build.json" },
-    { "path": "../typescript-estree/tsconfig.build.json" }
+    { "path": "../scope-manager/tsconfig.build.json" }
   ]
 }

packages/eslint-plugin/tsconfig.json

@@ -4,5 +4,10 @@
     "composite": false,
     "rootDir": "."
   },
-  "include": ["src", "typings", "tests", "tools"]
+  "include": ["src", "typings", "tests", "tools"],
+  "references": [
+    { "path": "../experimental-utils/tsconfig.build.json" },
+    { "path": "../parser/tsconfig.build.json" },
+    { "path": "../scope-manager/tsconfig.build.json" }
+  ]
 }

packages/experimental-utils/tsconfig.json

@@ -4,5 +4,10 @@
     "composite": false,
     "rootDir": "."
   },
-  "include": ["src", "typings", "tests", "tools"]
+  "include": ["src", "typings", "tests", "tools"],
+  "references": [
+    { "path": "../scope-manager/tsconfig.build.json" },
+    { "path": "../types/tsconfig.build.json" },
+    { "path": "../typescript-estree/tsconfig.build.json" }
+  ]
 }

packages/parser/tsconfig.build.json

@@ -9,9 +9,9 @@
   "include": ["src"],
   "references": [
     { "path": "../experimental-utils/tsconfig.build.json" },
-    { "path": "../types/tsconfig.build.json" },
-    { "path": "../typescript-estree/tsconfig.build.json" },
     { "path": "../scope-manager/tsconfig.build.json" },
-    { "path": "../shared-fixtures/tsconfig.build.json" }
+    { "path": "../shared-fixtures/tsconfig.build.json" },
+    { "path": "../types/tsconfig.build.json" },
+    { "path": "../typescript-estree/tsconfig.build.json" }
   ]
 }

packages/parser/tsconfig.json

@@ -5,5 +5,12 @@
     "rootDir": "."
   },
   "include": ["src", "tests", "tools"],
-  "exclude": ["tests/fixtures"]
+  "exclude": ["tests/fixtures"],
+  "references": [
+    { "path": "../experimental-utils/tsconfig.build.json" },
+    { "path": "../scope-manager/tsconfig.build.json" },
+    { "path": "../shared-fixtures/tsconfig.build.json" },
+    { "path": "../types/tsconfig.build.json" },
+    { "path": "../typescript-estree/tsconfig.build.json" }
+  ]
 }

packages/scope-manager/tsconfig.json

@@ -4,5 +4,10 @@
     "composite": false,
     "rootDir": "."
   },
-  "include": ["src", "typings", "tests", "tools"]
+  "include": ["src", "typings", "tests", "tools"],
+  "references": [
+    { "path": "../types/tsconfig.build.json" },
+    { "path": "../typescript-estree/tsconfig.build.json" },
+    { "path": "../visitor-keys/tsconfig.build.json" }
+  ]
 }

packages/types/src/parser-options.ts

@@ -37,6 +37,7 @@ interface ParserOptions {
   debugLevel?: DebugLevel;
   errorOnTypeScriptSyntacticAndSemanticIssues?: boolean;
   errorOnUnknownASTType?: boolean;
+  EXPERIMENTAL_useSourceOfProjectReferenceRedirect?: boolean; // purposely undocumented for now
   extraFileExtensions?: string[];
   filePath?: string;
   loc?: boolean;

packages/typescript-estree/README.md

@@ -152,6 +152,18 @@ interface ParseAndGenerateServicesOptions extends ParseOptions {
    */
   errorOnTypeScriptSyntacticAndSemanticIssues?: boolean;
 
+  /**
+   * ***EXPERIMENTAL FLAG*** - Use this at your own risk.
+   *
+   * Causes TS to use the source files for referenced projects instead of the compiled .d.ts files.
+   * This feature is not yet optimized, and is likely to cause OOMs for medium to large projects.
+   *
+   * This flag REQUIRES at least TS v3.9, otherwise it does nothing.
+   *
+   * See: https://github.com/typescript-eslint/typescript-eslint/issues/2094
+   */
+  EXPERIMENTAL_useSourceOfProjectReferenceRedirect?: boolean;
+
   /**
    * When `project` is provided, this controls the non-standard file extensions which will be parsed.
    * It accepts an array of file extensions, each preceded by a `.`.

packages/typescript-estree/src/create-program/createWatchProgram.ts

@@ -117,6 +117,20 @@ function createHash(content: string): string {
   return content;
 }
 
+function updateCachedFileList(
+  tsconfigPath: CanonicalPath,
+  program: ts.Program,
+  extra: Extra,
+): Set<CanonicalPath> {
+  const fileList = extra.EXPERIMENTAL_useSourceOfProjectReferenceRedirect
+    ? new Set(
+        program.getSourceFiles().map(sf => getCanonicalFileName(sf.fileName)),
+      )
+    : new Set(program.getRootFileNames().map(f => getCanonicalFileName(f)));
+  programFileListCache.set(tsconfigPath, fileList);
+  return fileList;
+}
+
 /**
  * Calculate project environments using options provided by consumer and paths from config
  * @param code The code being linted
@@ -154,21 +168,12 @@ function getProgramsForProjects(
    * before we go into the process of attempting to find and update every program
    * see if we know of a program that contains this file
    */
-  for (const rawTsconfigPath of extra.projects) {
-    const tsconfigPath = getTsconfigPath(rawTsconfigPath, extra);
-    const existingWatch = knownWatchProgramMap.get(tsconfigPath);
-    if (!existingWatch) {
-      continue;
-    }
-
+  for (const [tsconfigPath, existingWatch] of knownWatchProgramMap.entries()) {
     let fileList = programFileListCache.get(tsconfigPath);
     let updatedProgram: ts.Program | null = null;
     if (!fileList) {
       updatedProgram = existingWatch.getProgram().getProgram();
-      fileList = new Set(
-        updatedProgram.getRootFileNames().map(f => getCanonicalFileName(f)),
-      );
-      programFileListCache.set(tsconfigPath, fileList);
+      fileList = updateCachedFileList(tsconfigPath, updatedProgram, extra);
     }
 
     if (fileList.has(filePath)) {
@@ -209,18 +214,38 @@ function getProgramsForProjects(
 
       // sets parent pointers in source files
       updatedProgram.getTypeChecker();
-      results.push(updatedProgram);
 
+      // cache and check the file list
+      const fileList = updateCachedFileList(
+        tsconfigPath,
+        updatedProgram,
+        extra,
+      );
+      if (fileList.has(filePath)) {
+        log('Found updated program for file. %s', filePath);
+        // we can return early because we know this program contains the file
+        return [updatedProgram];
+      }
+
+      results.push(updatedProgram);
       continue;
     }
 
     const programWatch = createWatchProgram(tsconfigPath, extra);
-    const program = programWatch.getProgram().getProgram();
-
-    // cache watch program and return current program
     knownWatchProgramMap.set(tsconfigPath, programWatch);
+
+    const program = programWatch.getProgram().getProgram();
     // sets parent pointers in source files
     program.getTypeChecker();
+
+    // cache and check the file list
+    const fileList = updateCachedFileList(tsconfigPath, program, extra);
+    if (fileList.has(filePath)) {
+      log('Found program for file. %s', filePath);
+      // we can return early because we know this program contains the file
+      return [program];
+    }
+
     results.push(program);
   }
 
@@ -324,6 +349,13 @@ function createWatchProgram(
   );
   watchCompilerHost.trace = log;
 
+  /**
+   * TODO: this needs refinement and development, but we're allowing users to opt-in to this for now for testing and feedback.
+   * See https://github.com/typescript-eslint/typescript-eslint/issues/2094
+   */
+  watchCompilerHost.useSourceOfProjectReferenceRedirect = (): boolean =>
+    extra.EXPERIMENTAL_useSourceOfProjectReferenceRedirect;
+
   // Since we don't want to asynchronously update program we want to disable timeout methods
   // So any changes in the program will be delayed and updated when getProgram is called on watch
   let callback: (() => void) | undefined;

packages/typescript-estree/src/parser-options.ts

@@ -12,6 +12,7 @@ export interface Extra {
   debugLevel: Set<DebugModule>;
   errorOnTypeScriptSyntacticAndSemanticIssues: boolean;
   errorOnUnknownASTType: boolean;
+  EXPERIMENTAL_useSourceOfProjectReferenceRedirect: boolean;
   extraFileExtensions: string[];
   filePath: string;
   jsx: boolean;
@@ -111,6 +112,18 @@ interface ParseAndGenerateServicesOptions extends ParseOptions {
    */
   errorOnTypeScriptSyntacticAndSemanticIssues?: boolean;
 
+  /**
+   * ***EXPERIMENTAL FLAG*** - Use this at your own risk.
+   *
+   * Causes TS to use the source files for referenced projects instead of the compiled .d.ts files.
+   * This feature is not yet optimized, and is likely to cause OOMs for medium to large projects.
+   *
+   * This flag REQUIRES at least TS v3.9, otherwise it does nothing.
+   *
+   * See: https://github.com/typescript-eslint/typescript-eslint/issues/2094
+   */
+  EXPERIMENTAL_useSourceOfProjectReferenceRedirect?: boolean;
+
   /**
    * When `project` is provided, this controls the non-standard file extensions which will be parsed.
    * It accepts an array of file extensions, each preceded by a `.`.

packages/typescript-estree/src/parser.ts

@@ -93,6 +93,7 @@ function resetExtra(): void {
     debugLevel: new Set(),
     errorOnTypeScriptSyntacticAndSemanticIssues: false,
     errorOnUnknownASTType: false,
+    EXPERIMENTAL_useSourceOfProjectReferenceRedirect: false,
     extraFileExtensions: [],
     filePath: getFileName(),
     jsx: false,
@@ -168,7 +169,7 @@ function applyParserOptionsToExtra(options: TSESTreeOptions): void {
     if (
       extra.debugLevel.has('eslint') ||
       // make sure we don't turn off the eslint debug if it was enabled via --debug
-      debug.enabled('eslint:*')
+      debug.enabled('eslint:*,-eslint:code-path')
     ) {
       // https://github.com/eslint/eslint/blob/9dfc8501fb1956c90dc11e6377b4cb38a6bea65d/bin/eslint.js#L25
       namespaces.push('eslint:*,-eslint:code-path');
@@ -284,6 +285,10 @@ function applyParserOptionsToExtra(options: TSESTreeOptions): void {
   extra.createDefaultProgram =
     typeof options.createDefaultProgram === 'boolean' &&
     options.createDefaultProgram;
+
+  extra.EXPERIMENTAL_useSourceOfProjectReferenceRedirect =
+    typeof options.EXPERIMENTAL_useSourceOfProjectReferenceRedirect ===
+      'boolean' && options.EXPERIMENTAL_useSourceOfProjectReferenceRedirect;
 }
 
 function warnAboutTSVersion(): void {

packages/typescript-estree/tsconfig.build.json

@@ -6,5 +6,10 @@
     "rootDir": "./src",
     "resolveJsonModule": true
   },
-  "include": ["src", "typings"]
+  "include": ["src", "typings"],
+  "references": [
+    { "path": "../shared-fixtures/tsconfig.build.json" },
+    { "path": "../types/tsconfig.build.json" },
+    { "path": "../visitor-keys/tsconfig.build.json" }
+  ]
 }