Ensure that when new file affecting global scope is added, the signatures are updated

src/compiler/builder.ts

@@ -438,8 +438,23 @@ namespace ts {
                     removeSemanticDiagnosticsOf(state, f.resolvedPath)
                 );
             }
+            // When a change affects the global scope, all files are considered to be affected without updating their signature
+            // That means when affected file is handled, its signature can be out of date
+            // To avoid this, ensure that we update the signature for any affected file in this scenario.
+            BuilderState.updateShapeSignature(
+                state,
+                Debug.checkDefined(state.program),
+                affectedFile,
+                Debug.checkDefined(state.currentAffectedFilesSignatures),
+                cancellationToken,
+                computeHash,
+                state.currentAffectedFilesExportedModulesMap
+            );
             return;
         }
+        else {
+            Debug.assert(state.hasCalledUpdateShapeSignature.has(affectedFile.resolvedPath) || state.currentAffectedFilesSignatures?.has(affectedFile.resolvedPath), `Signature not updated for affected file: ${affectedFile.fileName}`);
+        }
 
         if (!state.compilerOptions.assumeChangesOnlyAffectDirectDependencies) {
             forEachReferencingModulesOfExportOfAffectedFile(state, affectedFile, (state, path) => handleDtsMayChangeOf(state, path, cancellationToken, computeHash));

src/testRunner/unittests/tsc/incremental.ts

@@ -236,6 +236,58 @@ const a: string = 10;`, "utf-8"),
             }
         });
 
+        verifyTscSerializedIncrementalEdits({
+            scenario: "incremental",
+            subScenario: `when global file is added, the signatures are updated`,
+            fs: () => loadProjectFromFiles({
+                "/src/project/src/main.ts": Utils.dedent`
+                    /// <reference path="./filePresent.ts"/>
+                    /// <reference path="./fileNotFound.ts"/>
+                    function main() { }
+                `,
+                "/src/project/src/anotherFileWithSameReferenes.ts": Utils.dedent`
+                    /// <reference path="./filePresent.ts"/>
+                    /// <reference path="./fileNotFound.ts"/>
+                    function anotherFileWithSameReferenes() { }
+                `,
+                "/src/project/src/filePresent.ts": `function something() { return 10; }`,
+                "/src/project/tsconfig.json": JSON.stringify({
+                    compilerOptions: { composite: true, },
+                    include: ["src/**/*.ts"]
+                }),
+            }),
+            commandLineArgs: ["--p", "src/project"],
+            incrementalScenarios: [
+                noChangeRun,
+                {
+                    subScenario: "Modify main file",
+                    buildKind: BuildKind.IncrementalDtsChange,
+                    modifyFs: fs => appendText(fs, `/src/project/src/main.ts`, `something();`),
+                },
+                {
+                    subScenario: "Add new file and update main file",
+                    buildKind: BuildKind.IncrementalDtsChange,
+                    modifyFs: fs => {
+                        fs.writeFileSync(`/src/project/src/newFile.ts`, "function foo() { return 20; }");
+                        prependText(fs, `/src/project/src/main.ts`, `/// <reference path="./newFile.ts"/>
+`);
+                        appendText(fs, `/src/project/src/main.ts`, `foo();`);
+                    },
+                },
+                {
+                    subScenario: "Write file that could not be resolved",
+                    buildKind: BuildKind.IncrementalDtsChange,
+                    modifyFs: fs => fs.writeFileSync(`/src/project/src/fileNotFound.ts`, "function something2() { return 20; }"),
+                },
+                {
+                    subScenario: "Modify main file",
+                    buildKind: BuildKind.IncrementalDtsChange,
+                    modifyFs: fs => appendText(fs, `/src/project/src/main.ts`, `something();`),
+                },
+            ],
+            baselinePrograms: true,
+        });
+
         const jsxLibraryContent = `
 export {};
 declare global {