feat: update headText

Fix handling of namespaces.
Add tests.

src/head-text.test.ts

@@ -0,0 +1,65 @@
+import dedent from "ts-dedent";
+import {
+  ModuleKind,
+  ModuleResolutionKind,
+  Project,
+  ScriptTarget,
+} from "ts-morph";
+import { expect, test } from "vitest";
+import { headText } from "./head-text";
+
+test("return text from declaration before body without JSDoc", () => {
+  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`
+    /** Docs for FooInterface */
+    interface FooInterface {
+      bar: number;
+    }
+
+    /** Docs for FooClass */
+    class FooClass extends FooInterface {
+      bar;
+      constructor() {
+        this.bar = 1;
+      }
+    }
+
+    /** Docs for FooEnum */
+    enum FooEnum {
+      Bar,
+      Baz
+    }
+
+    /** Docs for FooNamespace */
+    namespace FooNamespace {
+      /** Docs for FooNamespaceClass */
+      class FooNamespaceClass {
+        bar;
+        constructor() {
+          this.bar = 1;
+        }
+      }
+    }
+    `,
+  );
+  expect(headText(indexFile.getInterfaceOrThrow("FooInterface"))).toBe(
+    "interface FooInterface {}",
+  );
+  expect(headText(indexFile.getClassOrThrow("FooClass"))).toBe(
+    "class FooClass extends FooInterface {}",
+  );
+  expect(headText(indexFile.getEnumOrThrow("FooEnum"))).toBe("enum FooEnum {}");
+  expect(headText(indexFile.getModuleOrThrow("FooNamespace"))).toBe(
+    "namespace FooNamespace {}",
+  );
+});

src/head-text.ts

@@ -21,7 +21,11 @@ export const headText = (
     }
     if (node.getKind() === SyntaxKind.OpenBraceToken) {
       // Stop at body start, marked by the first `{`
-      // found in a class or interface declaration.
+      // found in a class, interface or enum declaration.
+      break;
+    }
+    if (node.getKind() === SyntaxKind.ModuleBlock) {
+      // Stop at module body start, found in a namespace declaration.
       break;
     }
     parts.push(node.getText());