Add declaration paths to remap cache in packages mode

Resolves #2416

Author: Gerrit0

Diff for: CHANGELOG.md

@@ -3,6 +3,7 @@
 ### Features
 
 -   Added `--sourceLinkExternal` option to render source code links as external, #2415.
+-   TypeDoc no longer requires the `declarationMap` option to be set to true to handle cross-package links in packages mode, #2416.
 -   Added `external-last` option for the `--sort` option, #2418.
 
 ### Bug Fixes

Diff for: src/lib/application.ts

@@ -41,6 +41,7 @@ import { ApplicationEvents } from "./application-events";
 import { findTsConfigFile } from "./utils/tsconfig";
 import { deriveRootDir, glob, readFile } from "./utils/fs";
 import { resetReflectionID } from "./models/reflections/abstract";
+import { addInferredDeclarationMapPaths } from "./models/reflections/ReflectionSymbolId";
 
 // eslint-disable-next-line @typescript-eslint/no-var-requires
 const packageInfo = require("../../package.json") as {
@@ -590,9 +591,10 @@ export class Application extends ChildableComponent<
         const origOptions = this.options;
         const projects: JSONOutput.ProjectReflection[] = [];
 
+        const projectsToConvert: { dir: string; options: Options }[] = [];
         // Generate a json file for each package
         for (const dir of packageDirs) {
-            this.logger.info(`Converting project at ${nicePath(dir)}`);
+            this.logger.verbose(`Reading project at ${nicePath(dir)}`);
             const opts = origOptions.copyForPackage(dir);
             await opts.read(this.logger, dir);
             // Invalid links should only be reported after everything has been merged.
@@ -609,7 +611,17 @@ export class Application extends ChildableComponent<
                 continue;
             }
 
-            this.options = opts;
+            addInferredDeclarationMapPaths(
+                opts.getCompilerOptions(),
+                opts.getFileNames(),
+            );
+
+            projectsToConvert.push({ dir, options: opts });
+        }
+
+        for (const { dir, options } of projectsToConvert) {
+            this.logger.info(`Converting project at ${nicePath(dir)}`);
+            this.options = options;
             const project = await this.convert();
             if (project) {
                 this.validate(project);

Diff for: src/lib/models/reflections/ReflectionSymbolId.ts

@@ -2,7 +2,7 @@ import { existsSync } from "fs";
 import { isAbsolute, join, relative, resolve } from "path";
 import ts from "typescript";
 import type { JSONOutput, Serializer } from "../../serialization/index";
-import { readFile } from "../../utils/fs";
+import { getCommonDirectory, readFile } from "../../utils/fs";
 import { getQualifiedName } from "../../utils/tsutils";
 import { optional, validate } from "../../utils/validation";
 import { normalizePath } from "../../utils/paths";
@@ -61,27 +61,26 @@ export class ReflectionSymbolId {
     }
 
     toObject(serializer: Serializer) {
+        const sourceFileName = isAbsolute(this.fileName)
+            ? normalizePath(
+                  relative(
+                      serializer.projectRoot,
+                      resolveDeclarationMaps(this.fileName),
+                  ),
+              )
+            : this.fileName;
+
         return {
-            sourceFileName: isAbsolute(this.fileName)
-                ? normalizePath(
-                      relative(
-                          serializer.projectRoot,
-                          resolveDeclarationMaps(this.fileName),
-                      ),
-                  )
-                : this.fileName,
+            sourceFileName,
             qualifiedName: this.qualifiedName,
         };
     }
 }
 
 const declarationMapCache = new Map<string, string>();
 
-/**
- * See also getTsSourceFromJsSource in package-manifest.ts.
- */
 function resolveDeclarationMaps(file: string): string {
-    if (!file.endsWith(".d.ts")) return file;
+    if (!/\.d\.[cm]?ts$/.test(file)) return file;
     if (declarationMapCache.has(file)) return declarationMapCache.get(file)!;
 
     const mapFile = file + ".map";
@@ -123,3 +122,19 @@ function resolveDeclarationMaps(file: string): string {
 
     return file;
 }
+
+export function addInferredDeclarationMapPaths(
+    opts: ts.CompilerOptions,
+    files: readonly string[],
+) {
+    const rootDir = opts.rootDir || getCommonDirectory(files);
+    const declDir = opts.declarationDir || opts.outDir || rootDir;
+
+    for (const file of files) {
+        const mapFile = resolve(declDir, relative(rootDir, file)).replace(
+            /\.([cm]?[tj]s)x?$/,
+            ".d.$1",
+        );
+        declarationMapCache.set(mapFile, file);
+    }
+}