Discrepancy when typeToString when enclosingDeclaration is undefined vs defined.

Bug Report

I'm using typeToString functionality from the typescript compiler (via ts-morph) to build auto-generated API documentation. I've run into an issue with certain types that use default generic types. My goals:

• I don't want the default parameters to show up
• I want the module/sourcefile import included

If I pass enclosingDeclaration, the default parameters don't show up, but the import is gone. If I don't pass enclosingDeclaration the opposite happens - import is there, but the default parameters show up.

🔎 Search Terms

Typescript typeToString generic optional default parameter ignore enclosingDeclaration

🕗 Version & Regression Information

I'm not sure this is bug but there is nothing I could find about it anywhere else.

⏯ Playground Link

link

Code sandbox which shows the issue.

💻 Code

Types:

export interface WithDefaultGenerics<A = string, B = number> {
  irrelevant: string;
}

export type Test = () => WithDefaultGenerics;

    const text = compiler.typeToString(
      compilerType, // This is the type of `Test`
      undefined,
      TypeFormatFlags.UseFullyQualifiedType | TypeFormatFlags.InTypeAlias
    );
    console.log('text is ', text);

    const text2 = compiler.typeToString(
      compilerType, // This is the type of `Test`
      node.compilerNode, // This is the node container of `Test`
      TypeFormatFlags.UseFullyQualifiedType | TypeFormatFlags.InTypeAlias
    );
    console.log('text2 is ', text2);

🙁 Actual behavior

text is  () => import("/Users/path/to/file").WithDefaultGenerics<string, number>

text2 is  () => WithDefaultGenerics

🙂 Expected behavior

I'm trying to get () => import("/Users/path/to/file").WithDefaultGenerics

The reason this is important to me is because in conjunction with, I suspect, this issue, getting a type for (props: AllCasesProps) => ReactElement<AllCasesProps> ends up looking like this:

Beginne mit dem Playground-Link und den compiler typeToString-Aufrufen im Bericht und vergleiche die Ausgabe, wenn enclosingDeclaration nicht definiert ist, mit der Ausgabe, wenn es node.compilerNode ist. Untersuche, wie TypeFormatFlags.UseFullyQualifiedType und InTypeAlias die standardmäßigen generischen Argumente und modulqualifizierten Namen beeinflussen. Als erledigt gilt die Erzeugung des angeforderten qualifizierten Typs ohne Anzeige von Standardparametern, mit Regressionstests für beide Fälle.