Do not overwrite computed .d.ts signatures with file versions; add disableUseFileVersionAsSignature to BuilderProgramHost

src/compiler/builder.ts

@@ -321,8 +321,9 @@ function hasSameKeys(
 function createBuilderProgramState(
     newProgram: Program,
     oldState: Readonly<ReusableBuilderProgramState> | undefined,
+    disableUseFileVersionAsSignature?: boolean,
 ): BuilderProgramState {
-    const state = BuilderState.create(newProgram, oldState, /*disableUseFileVersionAsSignature*/ false) as BuilderProgramState;
+    const state = BuilderState.create(newProgram, oldState, !!disableUseFileVersionAsSignature) as BuilderProgramState;
     state.program = newProgram;
     const compilerOptions = newProgram.getCompilerOptions();
     state.compilerOptions = compilerOptions;
@@ -1682,7 +1683,7 @@ export function createBuilderProgram(
         return oldProgram;
     }
 
-    const state = createBuilderProgramState(newProgram, oldState);
+    const state = createBuilderProgramState(newProgram, oldState, host.disableUseFileVersionAsSignature);
     newProgram.getBuildInfo = () => getBuildInfo(toBuilderProgramStateWithDefinedProgram(state));
 
     // To ensure that we arent storing any references to old program or new program without state

src/compiler/builderPublic.ts

@@ -35,6 +35,14 @@ export interface BuilderProgramHost {
      * @internal
      */
     storeSignatureInfo?: boolean;
+    /**
+     * When true, the builder always computes .d.ts shape signatures for source files instead
+     * of falling back to the file version (text hash) on the initial program. This makes
+     * change detection precise from the first edit onward — at the cost of computing
+     * declaration signatures during the initial build — and avoids invalidating a file's
+     * entire dependent closure on the first edit after a fresh build.
+     */
+    disableUseFileVersionAsSignature?: boolean;
 }
 
 /** @internal */

src/compiler/builderState.ts

@@ -57,6 +57,7 @@ export enum SignatureInfo {
     ComputedDts,
     StoredSignatureAtEmit,
     UsedVersion,
+    KeptExistingSignature,
 }
 /** @internal */
 export interface BuilderState {
@@ -450,8 +451,20 @@ export namespace BuilderState {
         }
         // Default is to use file version as signature
         if (latestSignature === undefined) {
-            latestSignature = sourceFile.version;
-            if (host.storeSignatureInfo) (state.signatureInfo ??= new Map()).set(sourceFile.resolvedPath, SignatureInfo.UsedVersion);
+            // Do not overwrite a previously computed .d.ts signature with the file version:
+            // replacing it would make the next comparison against a freshly computed
+            // signature a guaranteed mismatch, falsely invalidating the file's entire
+            // dependent closure even for edits that do not change the file's shape.
+            // Keep the stored signature instead; use the version only when no computed
+            // signature exists.
+            if (!sourceFile.isDeclarationFile && !state.useFileVersionAsSignature && prevSignature !== undefined && prevSignature !== sourceFile.version) {
+                latestSignature = prevSignature;
+                if (host.storeSignatureInfo) (state.signatureInfo ??= new Map()).set(sourceFile.resolvedPath, SignatureInfo.KeptExistingSignature);
+            }
+            else {
+                latestSignature = sourceFile.version;
+                if (host.storeSignatureInfo) (state.signatureInfo ??= new Map()).set(sourceFile.resolvedPath, SignatureInfo.UsedVersion);
+            }
         }
         (state.oldSignatures ||= new Map()).set(sourceFile.resolvedPath, prevSignature || false);
         (state.hasCalledUpdateShapeSignature ||= new Set()).add(sourceFile.resolvedPath);

src/testRunner/unittests/helpers/baseline.ts

@@ -105,6 +105,10 @@ function baselineProgram(baseline: string[], [program, builderProgram]: CommandL
                             ts.Debug.assert(info?.version === info?.signature || !info?.signature);
                             baseline.push(path + " (used version)");
                             break;
+                        case ts.SignatureInfo.KeptExistingSignature:
+                            ts.Debug.assert(info?.signature && info.signature !== info.version);
+                            baseline.push(path + " (kept existing computed signature)");
+                            break;
                         default:
                             ts.Debug.assertNever(signatureInfo);
                     }

tests/baselines/reference/tsbuild/inferredTypeFromTransitiveModule/inferred-type-from-transitive-module-discrepancies.js

@@ -0,0 +1,20 @@
+0:: incremental-declaration-changes
+*** Needs explanation
+Incremental signature is neither dts signature nor file version for File:: ../index.ts
+Incremental:: {
+  "original": {
+    "version": "6186344161-import { LazyAction, LazyModule } from './bundling';\nconst lazyModule = new LazyModule(() =>\n    import('./lazyIndex')\n);\nexport const lazyBar = new LazyAction(lazyModule, m => m.bar);\n",
+    "signature": "-13696684486-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<(param: string) => void, typeof import(\"./lazyIndex\")>;\n"
+  },
+  "version": "6186344161-import { LazyAction, LazyModule } from './bundling';\nconst lazyModule = new LazyModule(() =>\n    import('./lazyIndex')\n);\nexport const lazyBar = new LazyAction(lazyModule, m => m.bar);\n",
+  "signature": "-13696684486-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<(param: string) => void, typeof import(\"./lazyIndex\")>;\n"
+}
+Clean:: {
+  "original": {
+    "version": "6186344161-import { LazyAction, LazyModule } from './bundling';\nconst lazyModule = new LazyModule(() =>\n    import('./lazyIndex')\n);\nexport const lazyBar = new LazyAction(lazyModule, m => m.bar);\n",
+    "signature": "-4053129224-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<() => void, typeof import(\"./lazyIndex\")>;\n"
+  },
+  "version": "6186344161-import { LazyAction, LazyModule } from './bundling';\nconst lazyModule = new LazyModule(() =>\n    import('./lazyIndex')\n);\nexport const lazyBar = new LazyAction(lazyModule, m => m.bar);\n",
+  "signature": "-4053129224-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<() => void, typeof import(\"./lazyIndex\")>;\n"
+}
+Dts Signature:: "-4053129224-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<() => void, typeof import(\"./lazyIndex\")>;\n"

tests/baselines/reference/tsbuild/inferredTypeFromTransitiveModule/inferred-type-from-transitive-module-with-isolatedModules-discrepancies.js

@@ -0,0 +1,20 @@
+0:: incremental-declaration-changes
+*** Needs explanation
+Incremental signature is neither dts signature nor file version for File:: ../index.ts
+Incremental:: {
+  "original": {
+    "version": "6186344161-import { LazyAction, LazyModule } from './bundling';\nconst lazyModule = new LazyModule(() =>\n    import('./lazyIndex')\n);\nexport const lazyBar = new LazyAction(lazyModule, m => m.bar);\n",
+    "signature": "-13696684486-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<(param: string) => void, typeof import(\"./lazyIndex\")>;\n"
+  },
+  "version": "6186344161-import { LazyAction, LazyModule } from './bundling';\nconst lazyModule = new LazyModule(() =>\n    import('./lazyIndex')\n);\nexport const lazyBar = new LazyAction(lazyModule, m => m.bar);\n",
+  "signature": "-13696684486-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<(param: string) => void, typeof import(\"./lazyIndex\")>;\n"
+}
+Clean:: {
+  "original": {
+    "version": "6186344161-import { LazyAction, LazyModule } from './bundling';\nconst lazyModule = new LazyModule(() =>\n    import('./lazyIndex')\n);\nexport const lazyBar = new LazyAction(lazyModule, m => m.bar);\n",
+    "signature": "-4053129224-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<() => void, typeof import(\"./lazyIndex\")>;\n"
+  },
+  "version": "6186344161-import { LazyAction, LazyModule } from './bundling';\nconst lazyModule = new LazyModule(() =>\n    import('./lazyIndex')\n);\nexport const lazyBar = new LazyAction(lazyModule, m => m.bar);\n",
+  "signature": "-4053129224-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<() => void, typeof import(\"./lazyIndex\")>;\n"
+}
+Dts Signature:: "-4053129224-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<() => void, typeof import(\"./lazyIndex\")>;\n"

tests/baselines/reference/tsbuild/inferredTypeFromTransitiveModule/inferred-type-from-transitive-module-with-isolatedModules.js

@@ -316,7 +316,7 @@ export declare const lazyBar: LazyAction<() => void, typeof import("./lazyIndex"
 
 
 //// [/home/src/workspaces/project/obj/tsconfig.tsbuildinfo]
-{"fileNames":["../../../tslibs/ts/lib/lib.es6.d.ts","../bar.ts","../bundling.ts","../global.d.ts","../lazyindex.ts","../index.ts"],"fileIdsList":[[3,5],[2]],"fileInfos":[{"version":"-25093698414-interface Boolean {}\ninterface Function {}\ninterface CallableFunction {}\ninterface NewableFunction {}\ninterface IArguments {}\ninterface Number { toExponential: any; }\ninterface Object {}\ninterface RegExp {}\ninterface String { charAt: any; }\ninterface Array<T> { length: number; [n: number]: T; }\ninterface ReadonlyArray<T> {}\ndeclare const console: { log(msg: any): void; };","affectsGlobalScope":true},{"version":"10075719182-interface RawAction {\n    (...args: any[]): Promise<any> | void;\n}\ninterface ActionFactory {\n    <T extends RawAction>(target: T): T;\n}\ndeclare function foo<U extends any[] = any[]>(): ActionFactory;\nexport default foo()(function foobar(): void {\n});\n","signature":"-1866892563-declare const _default: () => void;\nexport default _default;\n"},{"version":"-5105594088-export class LazyModule<TModule> {\n    constructor(private importCallback: () => Promise<TModule>) {}\n}\n\nexport class LazyAction<\n    TAction extends (...args: any[]) => any,\n    TModule\n>  {\n    constructor(_lazyModule: LazyModule<TModule>, _getter: (module: TModule) => TAction) {\n    }\n}\n","signature":"-23343356903-export declare class LazyModule<TModule> {\n    private importCallback;\n    constructor(importCallback: () => Promise<TModule>);\n}\nexport declare class LazyAction<TAction extends (...args: any[]) => any, TModule> {\n    constructor(_lazyModule: LazyModule<TModule>, _getter: (module: TModule) => TAction);\n}\n"},{"version":"-20910599262-interface PromiseConstructor {\n    new <T>(): Promise<T>;\n}\ndeclare var Promise: PromiseConstructor;\ninterface Promise<T> {\n}\n","affectsGlobalScope":true},"-6956449754-export { default as bar } from './bar';\n",{"version":"6186344161-import { LazyAction, LazyModule } from './bundling';\nconst lazyModule = new LazyModule(() =>\n    import('./lazyIndex')\n);\nexport const lazyBar = new LazyAction(lazyModule, m => m.bar);\n","signature":"-4053129224-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<() => void, typeof import(\"./lazyIndex\")>;\n"}],"root":[[2,6]],"options":{"declaration":true,"outDir":"./","target":2},"referencedMap":[[6,1],[5,2]],"semanticDiagnosticsPerFile":[[6,[{"start":97,"length":21,"messageText":"Dynamic imports are only supported when the '--module' flag is set to 'es2020', 'es2022', 'esnext', 'commonjs', 'amd', 'system', 'umd', 'node16', 'node18', 'node20', or 'nodenext'.","category":1,"code":1323}]]],"version":"FakeTSVersion"}
+{"fileNames":["../../../tslibs/ts/lib/lib.es6.d.ts","../bar.ts","../bundling.ts","../global.d.ts","../lazyindex.ts","../index.ts"],"fileIdsList":[[3,5],[2]],"fileInfos":[{"version":"-25093698414-interface Boolean {}\ninterface Function {}\ninterface CallableFunction {}\ninterface NewableFunction {}\ninterface IArguments {}\ninterface Number { toExponential: any; }\ninterface Object {}\ninterface RegExp {}\ninterface String { charAt: any; }\ninterface Array<T> { length: number; [n: number]: T; }\ninterface ReadonlyArray<T> {}\ndeclare const console: { log(msg: any): void; };","affectsGlobalScope":true},{"version":"10075719182-interface RawAction {\n    (...args: any[]): Promise<any> | void;\n}\ninterface ActionFactory {\n    <T extends RawAction>(target: T): T;\n}\ndeclare function foo<U extends any[] = any[]>(): ActionFactory;\nexport default foo()(function foobar(): void {\n});\n","signature":"-1866892563-declare const _default: () => void;\nexport default _default;\n"},{"version":"-5105594088-export class LazyModule<TModule> {\n    constructor(private importCallback: () => Promise<TModule>) {}\n}\n\nexport class LazyAction<\n    TAction extends (...args: any[]) => any,\n    TModule\n>  {\n    constructor(_lazyModule: LazyModule<TModule>, _getter: (module: TModule) => TAction) {\n    }\n}\n","signature":"-23343356903-export declare class LazyModule<TModule> {\n    private importCallback;\n    constructor(importCallback: () => Promise<TModule>);\n}\nexport declare class LazyAction<TAction extends (...args: any[]) => any, TModule> {\n    constructor(_lazyModule: LazyModule<TModule>, _getter: (module: TModule) => TAction);\n}\n"},{"version":"-20910599262-interface PromiseConstructor {\n    new <T>(): Promise<T>;\n}\ndeclare var Promise: PromiseConstructor;\ninterface Promise<T> {\n}\n","affectsGlobalScope":true},"-6956449754-export { default as bar } from './bar';\n",{"version":"6186344161-import { LazyAction, LazyModule } from './bundling';\nconst lazyModule = new LazyModule(() =>\n    import('./lazyIndex')\n);\nexport const lazyBar = new LazyAction(lazyModule, m => m.bar);\n","signature":"-13696684486-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<(param: string) => void, typeof import(\"./lazyIndex\")>;\n"}],"root":[[2,6]],"options":{"declaration":true,"outDir":"./","target":2},"referencedMap":[[6,1],[5,2]],"semanticDiagnosticsPerFile":[[6,[{"start":97,"length":21,"messageText":"Dynamic imports are only supported when the '--module' flag is set to 'es2020', 'es2022', 'esnext', 'commonjs', 'amd', 'system', 'umd', 'node16', 'node18', 'node20', or 'nodenext'.","category":1,"code":1323}]]],"version":"FakeTSVersion"}
 
 //// [/home/src/workspaces/project/obj/tsconfig.tsbuildinfo.readable.baseline.txt]
 {
@@ -379,10 +379,10 @@ export declare const lazyBar: LazyAction<() => void, typeof import("./lazyIndex"
     "../index.ts": {
       "original": {
         "version": "6186344161-import { LazyAction, LazyModule } from './bundling';\nconst lazyModule = new LazyModule(() =>\n    import('./lazyIndex')\n);\nexport const lazyBar = new LazyAction(lazyModule, m => m.bar);\n",
-        "signature": "-4053129224-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<() => void, typeof import(\"./lazyIndex\")>;\n"
+        "signature": "-13696684486-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<(param: string) => void, typeof import(\"./lazyIndex\")>;\n"
       },
       "version": "6186344161-import { LazyAction, LazyModule } from './bundling';\nconst lazyModule = new LazyModule(() =>\n    import('./lazyIndex')\n);\nexport const lazyBar = new LazyAction(lazyModule, m => m.bar);\n",
-      "signature": "-4053129224-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<() => void, typeof import(\"./lazyIndex\")>;\n"
+      "signature": "-13696684486-import { LazyAction } from './bundling';\nexport declare const lazyBar: LazyAction<(param: string) => void, typeof import(\"./lazyIndex\")>;\n"
     }
   },
   "root": [
@@ -429,7 +429,7 @@ export declare const lazyBar: LazyAction<() => void, typeof import("./lazyIndex"
     ]
   ],
   "version": "FakeTSVersion",
-  "size": 2682
+  "size": 2696
 }