Add test for tsbuildinfo text verification

src/testRunner/unittests/tscWatch/watchApi.ts

@@ -125,10 +125,15 @@ namespace ts.tscWatch {
     });
 
     describe("unittests:: tsc-watch:: watchAPI:: when watchHost uses createSemanticDiagnosticsBuilderProgram", () => {
-        it("verifies that noEmit is handled on createSemanticDiagnosticsBuilderProgram and typechecking happens only on affected files", () => {
+        function getWatch<T extends BuilderProgram>(config: File, optionsToExtend: CompilerOptions | undefined, sys: System, createProgram: CreateProgram<T>) {
+            const watchCompilerHost = createWatchCompilerHost(config.path, optionsToExtend, sys, createProgram);
+            return createWatchProgram(watchCompilerHost);
+        }
+
+        function setup<T extends BuilderProgram>(createProgram: CreateProgram<T>, configText: string) {
             const config: File = {
                 path: `${projectRoot}/tsconfig.json`,
-                content: "{}"
+                content: configText
             };
             const mainFile: File = {
                 path: `${projectRoot}/main.ts`,
@@ -139,13 +144,11 @@ namespace ts.tscWatch {
                 content: "export const y = 10;"
             };
             const sys = createWatchedSystem([config, mainFile, otherFile, libFile]);
-            const watchCompilerHost = createWatchCompilerHost(
-                config.path,
-                { noEmit: true },
-                sys,
-                createSemanticDiagnosticsBuilderProgram
-            );
-            const watch = createWatchProgram(watchCompilerHost);
+            const watch = getWatch(config, { noEmit: true }, sys, createProgram);
+            return { sys, watch, mainFile, otherFile, config };
+        }
+        it("verifies that noEmit is handled on createSemanticDiagnosticsBuilderProgram and typechecking happens only on affected files", () => {
+            const { sys, watch, mainFile, otherFile } = setup(createSemanticDiagnosticsBuilderProgram, "{}");
             checkProgramActualFiles(watch.getProgram().getProgram(), [mainFile.path, otherFile.path, libFile.path]);
             sys.appendFile(mainFile.path, "\n// SomeComment");
             sys.runQueuedTimeoutCallbacks();
@@ -154,5 +157,49 @@ namespace ts.tscWatch {
             // Should not retrieve diagnostics for other file thats not changed
             assert.deepEqual(program.getCachedSemanticDiagnostics(program.getSourceFile(otherFile.path)), /*expected*/ undefined);
         });
+
+        it("noEmit with composite writes the tsbuildinfo with pending affected files correctly", () => {
+            const configText = JSON.stringify({ compilerOptions: { composite: true } });
+            const { sys, watch, config, mainFile } = setup(createSemanticDiagnosticsBuilderProgram, configText);
+            const { sys: emitSys, watch: emitWatch } = setup(createEmitAndSemanticDiagnosticsBuilderProgram, configText);
+            verifyOutputs(sys, emitSys);
+
+            watch.close();
+            emitWatch.close();
+
+            // Emit on both sys should result in same output
+            verifyBuilder(createEmitAndSemanticDiagnosticsBuilderProgram, createEmitAndSemanticDiagnosticsBuilderProgram);
+
+            // Change file
+            sys.appendFile(mainFile.path, "\n// SomeComment");
+            emitSys.appendFile(mainFile.path, "\n// SomeComment");
+
+            // Verify noEmit results in same output
+            verifyBuilder(createSemanticDiagnosticsBuilderProgram, createEmitAndSemanticDiagnosticsBuilderProgram, { noEmit: true });
+
+            // Emit on both sys should result in same output
+            verifyBuilder(createEmitAndSemanticDiagnosticsBuilderProgram, createEmitAndSemanticDiagnosticsBuilderProgram);
+
+            // Change file
+            sys.appendFile(mainFile.path, "\n// SomeComment");
+            emitSys.appendFile(mainFile.path, "\n// SomeComment");
+
+            // Emit on both the builders should result in same files
+            verifyBuilder(createSemanticDiagnosticsBuilderProgram, createEmitAndSemanticDiagnosticsBuilderProgram);
+
+            function verifyOutputs(sys: System, emitSys: System) {
+                for (const output of [`${projectRoot}/main.js`, `${projectRoot}/main.d.ts`, `${projectRoot}/other.js`, `${projectRoot}/other.d.ts`, `${projectRoot}/tsconfig.tsbuildinfo`]) {
+                    assert.strictEqual(sys.readFile(output), emitSys.readFile(output), `Output file text for ${output}`);
+                }
+            }
+
+            function verifyBuilder<T extends BuilderProgram, U extends BuilderProgram>(createProgram: CreateProgram<T>, createEmitProgram: CreateProgram<U>, optionsToExtend?: CompilerOptions) {
+                const watch = getWatch(config, /*optionsToExtend*/ optionsToExtend, sys, createProgram);
+                const emitWatch = getWatch(config, /*optionsToExtend*/ optionsToExtend, emitSys, createEmitProgram);
+                verifyOutputs(sys, emitSys);
+                watch.close();
+                emitWatch.close();
+            }
+        });
     });
 }