feat: add getPackageOverview

Author: velut

src/get-package-overview.test.ts

@@ -0,0 +1,52 @@
+import { dedent } from "ts-dedent";
+import { ModuleKind, ModuleResolutionKind, Project, ScriptTarget } from "ts-morph";
+import { expect, test } from "vitest";
+import { getPackageOverview } from "./get-package-overview.ts";
+
+test("no overview", () => {
+	const project = new Project({
+		useInMemoryFileSystem: true,
+		compilerOptions: {
+			lib: ["lib.esnext.full.d.ts"],
+			target: ScriptTarget.ESNext,
+			module: ModuleKind.ESNext,
+			moduleResolution: ModuleResolutionKind.Bundler,
+		},
+	});
+	const indexFile = project.createSourceFile(
+		"index.ts",
+		dedent`
+    export {};
+    `,
+	);
+	expect(getPackageOverview(indexFile)).toBeUndefined();
+});
+
+test("with overview", () => {
+	const project = new Project({
+		useInMemoryFileSystem: true,
+		compilerOptions: {
+			lib: ["lib.esnext.full.d.ts"],
+			target: ScriptTarget.ESNext,
+			module: ModuleKind.ESNext,
+			moduleResolution: ModuleResolutionKind.Bundler,
+		},
+	});
+	const indexFile = project.createSourceFile(
+		"index.ts",
+		dedent`
+    /**
+    @packageDocumentation
+    This is the overview.
+    */
+
+    export {};
+    `,
+	);
+	expect(getPackageOverview(indexFile)).toBe(dedent`
+    /**
+    @packageDocumentation
+    This is the overview.
+    */
+    `);
+});

src/get-package-overview.ts

@@ -0,0 +1,9 @@
+import { SourceFile, SyntaxKind } from "ts-morph";
+
+export function getPackageOverview(indexFile: SourceFile): string | undefined {
+	return indexFile
+		.getDescendantsOfKind(SyntaxKind.JSDocTag)
+		.find((tag) => tag.getTagName() === "packageDocumentation")
+		?.getParentIfKind(SyntaxKind.JSDoc)
+		?.getText();
+}