Improve handling of function-modules created with Object.assign

Resolves #2436

Author: Gerrit0

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 -   Fixed default option values on options declared by plugins in packages mode, #2433.
 -   `gitRevision` will now be replaced in `sourceLinkTemplate`, #2434.
+-   Improved handling of function-modules created with `Object.assign`, #2436.
 -   Fixed an infinite loop when `skipLibCheck` is used to ignore some compiler errors, #2438.
 
 ### Thanks!

package.json

@@ -64,7 +64,7 @@
     "test": "mocha --config .config/mocha.fast.json",
     "test:cov": "c8 mocha --config .config/mocha.fast.json",
     "doc:c": "node bin/typedoc --tsconfig src/test/converter/tsconfig.json",
-    "doc:c2": "node --inspect-brk bin/typedoc --tsconfig src/test/converter2/tsconfig.json",
+    "doc:c2": "node bin/typedoc --tsconfig src/test/converter2/tsconfig.json",
     "test:full": "c8 mocha --config .config/mocha.full.json",
     "test:visual": "ts-node ./src/test/capture-screenshots.ts && ./scripts/compare_screenshots.sh",
     "test:visual:accept": "node scripts/accept_visual_regression.js",

src/lib/converter/symbols.ts

@@ -178,18 +178,6 @@ export function convertSymbol(
         flags = removeFlag(flags, ts.SymbolFlags.Property);
     }
 
-    // A default exported function with no associated variable is a property, but
-    // we should really convert it as a variable for documentation purposes
-    // export default () => {}
-    // export default 123
-    if (
-        flags === ts.SymbolFlags.Property &&
-        symbol.name === "default" &&
-        context.scope.kindOf(ReflectionKind.Module | ReflectionKind.Project)
-    ) {
-        flags = ts.SymbolFlags.BlockScopedVariable;
-    }
-
     for (const flag of getEnumFlags(flags ^ allConverterFlags)) {
         if (!(flag & allConverterFlags)) {
             context.logger.verbose(
@@ -645,6 +633,14 @@ function convertProperty(
     symbol: ts.Symbol,
     exportSymbol?: ts.Symbol,
 ) {
+    // This might happen if we're converting a function-module created with Object.assign
+    // or `export default () => {}`
+    if (
+        context.scope.kindOf(ReflectionKind.SomeModule | ReflectionKind.Project)
+    ) {
+        return convertVariable(context, symbol, exportSymbol);
+    }
+
     const declarations = symbol.getDeclarations() ?? [];
 
     // Don't do anything if we inherited this property and it is private.
@@ -1019,6 +1015,24 @@ function convertVariableAsFunction(
         );
     }
 
+    // #2436: Functions created with Object.assign on a function won't have a namespace flag
+    // but likely have properties that we should put into a namespace.
+    if (
+        type.getProperties().length &&
+        !hasAnyFlag(
+            symbol.flags,
+            ts.SymbolFlags.NamespaceModule | ts.SymbolFlags.ValueModule,
+        )
+    ) {
+        const ns = context.createDeclarationReflection(
+            ReflectionKind.Namespace,
+            symbol,
+            exportSymbol,
+        );
+        context.finalizeDeclarationReflection(ns);
+        convertSymbols(context.withScope(ns), type.getProperties());
+    }
+
     return ts.SymbolFlags.Property;
 }
 

src/test/converter2/issues/gh2436.ts

@@ -0,0 +1,17 @@
+/** The FOO function */
+function foo() {
+    return "foo";
+}
+
+function bugInner(): { foo: string } {
+    return { foo: "bar" };
+}
+
+export const bug: {
+    (): { foo: string };
+    foo: typeof foo;
+    bar: 42;
+} = Object.assign(bugInner, {
+    foo,
+    bar: 42 as const,
+});

src/test/issues.c2.test.ts

@@ -1197,6 +1197,22 @@ describe("Issue Tests", () => {
         );
     });
 
+    it("Handles function-namespaces created with Object.assign #2436", () => {
+        const project = convert();
+        equal(project.children?.map((c) => c.kind), [
+            ReflectionKind.Namespace,
+            ReflectionKind.Function,
+        ]);
+        equal(
+            project.children[0].getChildByName("bar")?.kind,
+            ReflectionKind.Variable,
+        );
+        equal(
+            project.children[0].getChildByName("foo")?.kind,
+            ReflectionKind.Function,
+        );
+    });
+
     it("Handles recursive aliases without looping infinitely #2438", () => {
         const bad = query(convert(), "Bad");
         equal(bad.kind, ReflectionKind.Interface);