[WIP] Caching resolutions in buildInfo and reusing them

src/compiler/builderPublic.ts

@@ -10,6 +10,7 @@ import {
     DiagnosticWithLocation,
     EmitResult,
     getBuilderCreationParameters,
+    OldBuildInfoProgramConstructor,
     Program,
     ProjectReference,
     ReusableBuilderProgramState,
@@ -63,6 +64,12 @@ export interface BuilderProgram {
      * @internal
      */
     getProgramOrUndefined(): Program | undefined;
+    /**
+     * Returns current program that could be undefined if the program was released, or cached build info program (currently module and type ref cache)
+     *
+     * @internal
+     */
+    getProgramOrOldBuildInfoProgramUndefined(): Program | OldBuildInfoProgramConstructor | undefined;
     /**
      * Releases reference to the program, making all the other operations that need program to fail.
      *

src/compiler/checker.ts

@@ -67,7 +67,6 @@ import {
     ClassLikeDeclaration,
     ClassStaticBlockDeclaration,
     clear,
-    combinePaths,
     compareDiagnostics,
     comparePaths,
     compareValues,
@@ -301,6 +300,7 @@ import {
     getOriginalNode,
     getOrUpdate,
     getOwnKeys,
+    getPackageJsonLocationFromScope,
     getParameterSymbolFromJSDoc,
     getParseTreeNode,
     getPropertyAssignmentAliasLikeExpression,
@@ -338,8 +338,8 @@ import {
     hasAccessorModifier,
     hasAmbientModifier,
     hasContextSensitiveParameters,
-    HasDecorators,
     hasDecorators,
+    HasDecorators,
     hasDynamicName,
     hasEffectiveModifier,
     hasEffectiveModifiers,
@@ -348,8 +348,8 @@ import {
     hasExtension,
     HasIllegalDecorators,
     HasIllegalModifiers,
-    HasInitializer,
     hasInitializer,
+    HasInitializer,
     hasJSDocNodes,
     hasJSDocParameterTags,
     hasJsonModuleEmitEnabled,
@@ -4730,19 +4730,19 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                             if (ext === Extension.Ts || ext === Extension.Js || ext === Extension.Tsx || ext === Extension.Jsx) {
                                 const scope = currentSourceFile.packageJsonScope;
                                 const targetExt = ext === Extension.Ts ? Extension.Mts : ext === Extension.Js ? Extension.Mjs : undefined;
-                                if (scope && !scope.contents.packageJsonContent.type) {
+                                if (scope?.contents && !scope.contents.packageJsonContent.type) {
                                     if (targetExt) {
                                         diagnosticDetails = chainDiagnosticMessages(
                                             /*details*/ undefined,
                                             Diagnostics.To_convert_this_file_to_an_ECMAScript_module_change_its_file_extension_to_0_or_add_the_field_type_Colon_module_to_1,
                                             targetExt,
-                                            combinePaths(scope.packageDirectory, "package.json"));
+                                            getPackageJsonLocationFromScope(scope));
                                     }
                                     else {
                                         diagnosticDetails = chainDiagnosticMessages(
                                             /*details*/ undefined,
                                             Diagnostics.To_convert_this_file_to_an_ECMAScript_module_add_the_field_type_Colon_module_to_0,
-                                            combinePaths(scope.packageDirectory, "package.json"));
+                                            getPackageJsonLocationFromScope(scope));
                                     }
                                 }
                                 else {

src/compiler/commandLineParser.ts

@@ -712,6 +712,16 @@ const commandOptionsWithoutBuild: CommandLineOption[] = [
         defaultValueDescription: false,
         description: Diagnostics.Enable_constraints_that_allow_a_TypeScript_project_to_be_used_with_project_references,
     },
+    {
+        name: "cacheResolutions",
+        type: "boolean",
+        category: Diagnostics.Projects,
+        description: Diagnostics.Save_resolutions_into_tsbuildinfo_file_and_use_them_for_incremental_compilation,
+        affectsBuildInfo: true,
+        affectsModuleResolution: true,
+        transpileOptionValue: undefined,
+        defaultValueDescription: false,
+    },
     {
         name: "tsBuildInfoFile",
         type: "string",
@@ -2791,6 +2801,9 @@ export function convertToOptionsWithAbsolutePaths(options: CompilerOptions, toAb
     if (result.configFilePath) {
         result.configFilePath = toAbsolutePath(result.configFilePath);
     }
+    if (result.pathsBasePath) {
+        result.pathsBasePath = toAbsolutePath(result.pathsBasePath);
+    }
     return result;
 }
 

src/compiler/diagnosticMessages.json

@@ -5154,6 +5154,14 @@
         "category": "Message",
         "code": 6261
     },
+    "Directory '{0}' resolves to '{1}' scope according to cache.": {
+        "category": "Message",
+        "code": 6263
+    },
+    "Directory '{0}' has no containing package.json scope according to cache.": {
+        "category": "Message",
+        "code": 6264
+    },
 
     "Directory '{0}' has no containing package.json scope. Imports will not resolve.": {
         "category": "Message",
@@ -5915,6 +5923,10 @@
         "category": "Message",
         "code": 6718
     },
+    "Save resolutions into .tsbuildinfo file and use them for incremental compilation.": {
+        "category": "Message",
+        "code": 6719
+    },
     "Default catch clause variables as 'unknown' instead of 'any'.": {
         "category": "Message",
         "code": 6803

src/compiler/emitter.ts

@@ -811,7 +811,7 @@ export function emitFiles(resolver: EmitResolver, host: EmitHost, targetSourceFi
             emitSkipped = true;
             return;
         }
-        const buildInfo = host.getBuildInfo(bundle) || createBuildInfo(/*program*/ undefined, bundle);
+        const buildInfo = host.getBuildInfo(bundle, buildInfoPath) || createBuildInfo(/*program*/ undefined, bundle);
         // Pass buildinfo as additional data to avoid having to reparse
         writeFile(host, emitterDiagnostics, buildInfoPath, getBuildInfoText(buildInfo), /*writeByteOrderMark*/ false, /*sourceFiles*/ undefined, { buildInfo });
     }