When there is no change in file text for program, no need to update program (#51626)

* When fsEvent for change is repeated

* When trying to check if program is uptodate, read the files from disk to determine the version instead of delaying so that new program is not created if file contents have not changed

Author: sheetalkamat

src/compiler/tsbuildPublic.ts

@@ -436,7 +436,7 @@ function createSolutionBuilderState<T extends BuilderProgram>(watch: boolean, ho
     // State of the solution
     const baseCompilerOptions = getCompilerOptionsOfBuildOptions(options);
     const compilerHost = createCompilerHostFromProgramHost(host, () => state.projectCompilerOptions) as CompilerHost & ReadBuildProgramHost;
-    setGetSourceFileAsHashVersioned(compilerHost, host);
+    setGetSourceFileAsHashVersioned(compilerHost);
     compilerHost.getParsedCommandLine = fileName => parseConfigFile(state, fileName as ResolvedConfigFileName, toResolvedConfigFilePath(state, fileName as ResolvedConfigFileName));
     compilerHost.resolveModuleNames = maybeBind(host, host.resolveModuleNames);
     compilerHost.resolveTypeReferenceDirectives = maybeBind(host, host.resolveTypeReferenceDirectives);

src/compiler/watch.ts

@@ -739,9 +739,9 @@ export function createWatchFactory<Y = undefined>(host: WatchFactoryHost & { tra
 export function createCompilerHostFromProgramHost(host: ProgramHost<any>, getCompilerOptions: () => CompilerOptions, directoryStructureHost: DirectoryStructureHost = host): CompilerHost {
     const useCaseSensitiveFileNames = host.useCaseSensitiveFileNames();
     const hostGetNewLine = memoize(() => host.getNewLine());
-    return {
+    const compilerHost: CompilerHost = {
         getSourceFile: createGetSourceFile(
-            (fileName, encoding) => host.readFile(fileName, encoding),
+            (fileName, encoding) => !encoding ? compilerHost.readFile(fileName) : host.readFile(fileName, encoding),
             getCompilerOptions,
             /*setParentNodes*/ undefined
         ),
@@ -768,6 +768,7 @@ export function createCompilerHostFromProgramHost(host: ProgramHost<any>, getCom
         disableUseFileVersionAsSignature: host.disableUseFileVersionAsSignature,
         storeFilesChangingSignatureDuringEmit: host.storeFilesChangingSignatureDuringEmit,
     };
+    return compilerHost;
 }
 
 /** @internal */
@@ -810,12 +811,12 @@ export function getSourceFileVersionAsHashFromText(host: Pick<CompilerHost, "cre
 }
 
 /** @internal */
-export function setGetSourceFileAsHashVersioned(compilerHost: CompilerHost, host: { createHash?(data: string): string; }) {
+export function setGetSourceFileAsHashVersioned(compilerHost: CompilerHost) {
     const originalGetSourceFile = compilerHost.getSourceFile;
     compilerHost.getSourceFile = (...args) => {
         const result = originalGetSourceFile.call(compilerHost, ...args);
         if (result) {
-            result.version = getSourceFileVersionAsHashFromText(host, result.text);
+            result.version = getSourceFileVersionAsHashFromText(compilerHost, result.text);
         }
         return result;
     };

src/compiler/watchPublic.ts

@@ -48,6 +48,7 @@ import {
     getNewLineCharacter,
     getNormalizedAbsolutePath,
     getParsedCommandLineOfConfigFile,
+    getSourceFileVersionAsHashFromText,
     getTsBuildInfoEmitOutputFilePath,
     HasInvalidatedResolutions,
     isArray,
@@ -121,7 +122,7 @@ export function createIncrementalCompilerHost(options: CompilerOptions, system =
     host.createHash = maybeBind(system, system.createHash);
     host.disableUseFileVersionAsSignature = system.disableUseFileVersionAsSignature;
     host.storeFilesChangingSignatureDuringEmit = system.storeFilesChangingSignatureDuringEmit;
-    setGetSourceFileAsHashVersioned(host, system);
+    setGetSourceFileAsHashVersioned(host);
     changeCompilerHostLikeToUseCache(host, fileName => toPath(fileName, host.getCurrentDirectory(), host.getCanonicalFileName));
     return host;
 }
@@ -429,7 +430,7 @@ export function createWatchProgram<T extends BuilderProgram>(host: WatchCompiler
     }
 
     const compilerHost = createCompilerHostFromProgramHost(host, () => compilerOptions, directoryStructureHost) as CompilerHost & ResolutionCacheHost;
-    setGetSourceFileAsHashVersioned(compilerHost, host);
+    setGetSourceFileAsHashVersioned(compilerHost);
     // Members for CompilerHost
     const getNewSourceFile = compilerHost.getSourceFile;
     compilerHost.getSourceFile = (fileName, ...args) => getVersionedSourceFileByPath(fileName, toPath(fileName), ...args);
@@ -551,9 +552,9 @@ export function createWatchProgram<T extends BuilderProgram>(host: WatchCompiler
         const hasInvalidatedResolutions = resolutionCache.createHasInvalidatedResolutions(customHasInvalidatedResolutions);
         const {
             originalReadFile, originalFileExists, originalDirectoryExists,
-            originalCreateDirectory, originalWriteFile,
+            originalCreateDirectory, originalWriteFile, readFileWithCache
         } = changeCompilerHostLikeToUseCache(compilerHost, toPath);
-        if (isProgramUptoDate(getCurrentProgram(), rootFileNames, compilerOptions, getSourceVersion, fileName => compilerHost.fileExists(fileName), hasInvalidatedResolutions, hasChangedAutomaticTypeDirectiveNames, getParsedCommandLine, projectReferences)) {
+        if (isProgramUptoDate(getCurrentProgram(), rootFileNames, compilerOptions, path => getSourceVersion(path, readFileWithCache), fileName => compilerHost.fileExists(fileName), hasInvalidatedResolutions, hasChangedAutomaticTypeDirectiveNames, getParsedCommandLine, projectReferences)) {
             if (hasChangedConfigFileParsingErrors) {
                 if (reportFileChangeDetectedOnCreateProgram) {
                     reportWatchDiagnostic(Diagnostics.File_change_detected_Starting_incremental_compilation);
@@ -708,9 +709,13 @@ export function createWatchProgram<T extends BuilderProgram>(host: WatchCompiler
         }
     }
 
-    function getSourceVersion(path: Path): string | undefined {
+    function getSourceVersion(path: Path, readFileWithCache: (file: string) => string | undefined): string | undefined {
         const hostSourceFile = sourceFilesCache.get(path);
-        return !hostSourceFile || !hostSourceFile.version ? undefined : hostSourceFile.version;
+        if (!hostSourceFile) return undefined;
+        if (hostSourceFile.version) return hostSourceFile.version;
+        // Read file and get new version
+        const text = readFileWithCache(path);
+        return text ? getSourceFileVersionAsHashFromText(compilerHost, text) : undefined;
     }
 
     function onReleaseOldSourceFile(oldSourceFile: SourceFile, _oldOptions: CompilerOptions, hasSourceFileByPath: boolean) {

src/testRunner/unittests/tscWatch/watchEnvironment.ts

@@ -702,4 +702,26 @@ describe("unittests:: tsc-watch:: watchEnvironment:: tsc-watch with different po
             ]
         });
     });
+
+    verifyTscWatch({
+        scenario,
+        subScenario: "fsEvent for change is repeated",
+        commandLineArgs: ["-w", "main.ts", "--extendedDiagnostics"],
+        sys: () => createWatchedSystem({
+            "/user/username/projects/project/main.ts": `let a: string = "Hello"`,
+            [libFile.path]: libFile.content,
+        }, { currentDirectory: "/user/username/projects/project" }),
+        changes: [
+            {
+                caption: "change main.ts",
+                change: sys => sys.replaceFileText("/user/username/projects/project/main.ts", "Hello", "Hello World"),
+                timeouts: sys => sys.runQueuedTimeoutCallbacks(),
+            },
+            {
+                caption: "receive another change event without modifying the file",
+                change: sys => sys.invokeFsWatches("/user/username/projects/project/main.ts", "change", /*modifiedTime*/ undefined, /*useTildeSuffix*/ undefined),
+                timeouts: sys => sys.runQueuedTimeoutCallbacks(),
+            }
+        ]
+    });
 });

src/testRunner/unittests/virtualFileSystemWithWatch.ts

@@ -686,7 +686,7 @@ export class TestServerHost implements server.ServerHost, FormatDiagnosticsHost,
         }
     }
 
-    private invokeFsWatches(fullPath: string, eventName: "rename" | "change", modifiedTime: Date | undefined, useTildeSuffix: boolean | undefined) {
+    invokeFsWatches(fullPath: string, eventName: "rename" | "change", modifiedTime: Date | undefined, useTildeSuffix: boolean | undefined) {
         this.invokeFsWatchesCallbacks(fullPath, eventName, modifiedTime, fullPath, useTildeSuffix);
         this.invokeFsWatchesCallbacks(getDirectoryPath(fullPath), eventName, modifiedTime, fullPath, useTildeSuffix);
         this.invokeRecursiveFsWatches(fullPath, eventName, modifiedTime, /*entryFullPath*/ undefined, useTildeSuffix);

tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError-with-incremental.js

@@ -183,30 +183,6 @@ Input::
 //// [/user/username/projects/noEmitOnError/src/main.ts] file written with same contents
 
 Output::
->> Screen clear
-[12:00:43 AM] File change detected. Starting incremental compilation...
-
-src/main.ts:4:1 - error TS1005: ',' expected.
-
-4 ;
-  ~
-
-[12:00:44 AM] Found 1 error. Watching for file changes.
-
-
-
-Program root files: ["/user/username/projects/noEmitOnError/shared/types/db.ts","/user/username/projects/noEmitOnError/src/main.ts","/user/username/projects/noEmitOnError/src/other.ts"]
-Program options: {"outDir":"/user/username/projects/noEmitOnError/dev-build","noEmitOnError":true,"watch":true,"assumeChangesOnlyAffectDirectDependencies":true,"incremental":true,"configFilePath":"/user/username/projects/noEmitOnError/tsconfig.json"}
-Program structureReused: Completely
-Program files::
-/a/lib/lib.d.ts
-/user/username/projects/noEmitOnError/shared/types/db.ts
-/user/username/projects/noEmitOnError/src/main.ts
-/user/username/projects/noEmitOnError/src/other.ts
-
-Semantic diagnostics in builder refreshed for::
-
-No shapes updated in the builder::
 
 PolledWatches::
 /user/username/projects/noemitonerror/node_modules/@types:
@@ -243,9 +219,9 @@ const a = {
 
 Output::
 >> Screen clear
-[[90m12:00:48 AM[0m] File change detected. Starting incremental compilation...
+[[90m12:00:46 AM[0m] File change detected. Starting incremental compilation...
 
-[[90m12:01:06 AM[0m] Found 0 errors. Watching for file changes.
+[[90m12:01:04 AM[0m] Found 0 errors. Watching for file changes.
 
 
 
@@ -382,14 +358,14 @@ const a: string = 10;
 
 Output::
 >> Screen clear
-[[90m12:01:13 AM[0m] File change detected. Starting incremental compilation...
+[[90m12:01:11 AM[0m] File change detected. Starting incremental compilation...
 
 src/main.ts:2:7 - error TS2322: Type 'number' is not assignable to type 'string'.
 
 2 const a: string = 10;
         ~
 
-[[90m12:01:17 AM[0m] Found 1 error. Watching for file changes.
+[[90m12:01:15 AM[0m] Found 1 error. Watching for file changes.
 
 
 
@@ -521,30 +497,6 @@ Input::
 //// [/user/username/projects/noEmitOnError/src/main.ts] file written with same contents
 
 Output::
->> Screen clear
-[12:01:25 AM] File change detected. Starting incremental compilation...
-
-src/main.ts:2:7 - error TS2322: Type 'number' is not assignable to type 'string'.
-
-2 const a: string = 10;
-        ~
-
-[12:01:26 AM] Found 1 error. Watching for file changes.
-
-
-
-Program root files: ["/user/username/projects/noEmitOnError/shared/types/db.ts","/user/username/projects/noEmitOnError/src/main.ts","/user/username/projects/noEmitOnError/src/other.ts"]
-Program options: {"outDir":"/user/username/projects/noEmitOnError/dev-build","noEmitOnError":true,"watch":true,"assumeChangesOnlyAffectDirectDependencies":true,"incremental":true,"configFilePath":"/user/username/projects/noEmitOnError/tsconfig.json"}
-Program structureReused: Completely
-Program files::
-/a/lib/lib.d.ts
-/user/username/projects/noEmitOnError/shared/types/db.ts
-/user/username/projects/noEmitOnError/src/main.ts
-/user/username/projects/noEmitOnError/src/other.ts
-
-Semantic diagnostics in builder refreshed for::
-
-No shapes updated in the builder::
 
 PolledWatches::
 /user/username/projects/noemitonerror/node_modules/@types:
@@ -579,9 +531,9 @@ const a: string = "hello";
 
 Output::
 >> Screen clear
-[[90m12:01:30 AM[0m] File change detected. Starting incremental compilation...
+[[90m12:01:26 AM[0m] File change detected. Starting incremental compilation...
 
-[[90m12:01:37 AM[0m] Found 0 errors. Watching for file changes.
+[[90m12:01:33 AM[0m] Found 0 errors. Watching for file changes.
 
 
 
@@ -701,25 +653,6 @@ Input::
 //// [/user/username/projects/noEmitOnError/src/main.ts] file written with same contents
 
 Output::
->> Screen clear
-[12:01:44 AM] File change detected. Starting incremental compilation...
-
-[12:01:45 AM] Found 0 errors. Watching for file changes.
-
-
-
-Program root files: ["/user/username/projects/noEmitOnError/shared/types/db.ts","/user/username/projects/noEmitOnError/src/main.ts","/user/username/projects/noEmitOnError/src/other.ts"]
-Program options: {"outDir":"/user/username/projects/noEmitOnError/dev-build","noEmitOnError":true,"watch":true,"assumeChangesOnlyAffectDirectDependencies":true,"incremental":true,"configFilePath":"/user/username/projects/noEmitOnError/tsconfig.json"}
-Program structureReused: Completely
-Program files::
-/a/lib/lib.d.ts
-/user/username/projects/noEmitOnError/shared/types/db.ts
-/user/username/projects/noEmitOnError/src/main.ts
-/user/username/projects/noEmitOnError/src/other.ts
-
-Semantic diagnostics in builder refreshed for::
-
-No shapes updated in the builder::
 
 PolledWatches::
 /user/username/projects/noemitonerror/node_modules/@types:

tests/baselines/reference/tscWatch/emitAndErrorUpdates/assumeChangesOnlyAffectDirectDependencies/with-noEmitOnError.js

@@ -103,30 +103,6 @@ Input::
 //// [/user/username/projects/noEmitOnError/src/main.ts] file written with same contents
 
 Output::
->> Screen clear
-[12:00:36 AM] File change detected. Starting incremental compilation...
-
-src/main.ts:4:1 - error TS1005: ',' expected.
-
-4 ;
-  ~
-
-[12:00:37 AM] Found 1 error. Watching for file changes.
-
-
-
-Program root files: ["/user/username/projects/noEmitOnError/shared/types/db.ts","/user/username/projects/noEmitOnError/src/main.ts","/user/username/projects/noEmitOnError/src/other.ts"]
-Program options: {"outDir":"/user/username/projects/noEmitOnError/dev-build","noEmitOnError":true,"watch":true,"assumeChangesOnlyAffectDirectDependencies":true,"configFilePath":"/user/username/projects/noEmitOnError/tsconfig.json"}
-Program structureReused: Completely
-Program files::
-/a/lib/lib.d.ts
-/user/username/projects/noEmitOnError/shared/types/db.ts
-/user/username/projects/noEmitOnError/src/main.ts
-/user/username/projects/noEmitOnError/src/other.ts
-
-Semantic diagnostics in builder refreshed for::
-
-No shapes updated in the builder::
 
 PolledWatches::
 /user/username/projects/noemitonerror/node_modules/@types:
@@ -163,9 +139,9 @@ const a = {
 
 Output::
 >> Screen clear
-[[90m12:00:41 AM[0m] File change detected. Starting incremental compilation...
+[[90m12:00:39 AM[0m] File change detected. Starting incremental compilation...
 
-[[90m12:00:58 AM[0m] Found 0 errors. Watching for file changes.
+[[90m12:00:56 AM[0m] Found 0 errors. Watching for file changes.
 
 
 
@@ -236,14 +212,14 @@ const a: string = 10;
 
 Output::
 >> Screen clear
-[[90m12:01:02 AM[0m] File change detected. Starting incremental compilation...
+[[90m12:01:00 AM[0m] File change detected. Starting incremental compilation...
 
 src/main.ts:2:7 - error TS2322: Type 'number' is not assignable to type 'string'.
 
 2 const a: string = 10;
         ~
 
-[[90m12:01:03 AM[0m] Found 1 error. Watching for file changes.
+[[90m12:01:01 AM[0m] Found 1 error. Watching for file changes.
 
 
 
@@ -291,30 +267,6 @@ Input::
 //// [/user/username/projects/noEmitOnError/src/main.ts] file written with same contents
 
 Output::
->> Screen clear
-[12:01:08 AM] File change detected. Starting incremental compilation...
-
-src/main.ts:2:7 - error TS2322: Type 'number' is not assignable to type 'string'.
-
-2 const a: string = 10;
-        ~
-
-[12:01:09 AM] Found 1 error. Watching for file changes.
-
-
-
-Program root files: ["/user/username/projects/noEmitOnError/shared/types/db.ts","/user/username/projects/noEmitOnError/src/main.ts","/user/username/projects/noEmitOnError/src/other.ts"]
-Program options: {"outDir":"/user/username/projects/noEmitOnError/dev-build","noEmitOnError":true,"watch":true,"assumeChangesOnlyAffectDirectDependencies":true,"configFilePath":"/user/username/projects/noEmitOnError/tsconfig.json"}
-Program structureReused: Completely
-Program files::
-/a/lib/lib.d.ts
-/user/username/projects/noEmitOnError/shared/types/db.ts
-/user/username/projects/noEmitOnError/src/main.ts
-/user/username/projects/noEmitOnError/src/other.ts
-
-Semantic diagnostics in builder refreshed for::
-
-No shapes updated in the builder::
 
 PolledWatches::
 /user/username/projects/noemitonerror/node_modules/@types:
@@ -349,9 +301,9 @@ const a: string = "hello";
 
 Output::
 >> Screen clear
-[[90m12:01:13 AM[0m] File change detected. Starting incremental compilation...
+[[90m12:01:09 AM[0m] File change detected. Starting incremental compilation...
 
-[[90m12:01:17 AM[0m] Found 0 errors. Watching for file changes.
+[[90m12:01:13 AM[0m] Found 0 errors. Watching for file changes.
 
 
 
@@ -405,25 +357,6 @@ Input::
 //// [/user/username/projects/noEmitOnError/src/main.ts] file written with same contents
 
 Output::
->> Screen clear
-[12:01:21 AM] File change detected. Starting incremental compilation...
-
-[12:01:22 AM] Found 0 errors. Watching for file changes.
-
-
-
-Program root files: ["/user/username/projects/noEmitOnError/shared/types/db.ts","/user/username/projects/noEmitOnError/src/main.ts","/user/username/projects/noEmitOnError/src/other.ts"]
-Program options: {"outDir":"/user/username/projects/noEmitOnError/dev-build","noEmitOnError":true,"watch":true,"assumeChangesOnlyAffectDirectDependencies":true,"configFilePath":"/user/username/projects/noEmitOnError/tsconfig.json"}
-Program structureReused: Completely
-Program files::
-/a/lib/lib.d.ts
-/user/username/projects/noEmitOnError/shared/types/db.ts
-/user/username/projects/noEmitOnError/src/main.ts
-/user/username/projects/noEmitOnError/src/other.ts
-
-Semantic diagnostics in builder refreshed for::
-
-No shapes updated in the builder::
 
 PolledWatches::
 /user/username/projects/noemitonerror/node_modules/@types: