git.test: cover the ucrt64 axis

Add a `getViaGit full ucrt64` companion to the existing
`getViaGit full x86_64` test. The new test pins down the two
behaviours that distinguish the UCRT64 variant from the MINGW64 one,
both of which would silently regress to "secretly materialise the
wrong toolchain" if broken: that the artifact name is
`git-sdk-ucrt64-full` rather than `git-sdk-64-full` (so caches and
on-disk output directories never collide with `x86_64`), and that the
clone targets the `ucrt64` branch of `git-sdk-64` rather than `main`.

The clone assertion goes via `spawnAndWaitForExitCode` rather than
spying on `clone` itself, because internal callers of `clone()` within
`git.ts` resolve the binding at module load time and the `vi.spyOn`
override of the module export does not intercept them. The existing
`full x86_64` test only mocks `clone` to silence side-effects, never
to assert on its arguments, so the discrepancy in style is local to
this one new test.

Assisted-by: Opus 4.7
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

src/__tests__/git.test.ts

@@ -98,4 +98,37 @@ describe('git', () => {
     )
     expect(fs.rmSync).toHaveBeenCalledWith('.tmp', {recursive: true})
   })
+
+  test('getViaGit full ucrt64', async () => {
+    const flavor = 'full'
+    const architecture = 'ucrt64'
+    const outputDirectory = 'outputDirectory'
+
+    const spawnSpy = vi
+      .spyOn(spawn, 'spawnAndWaitForExitCode')
+      .mockResolvedValue({
+        exitCode: 0
+      })
+
+    const {artifactName, download} = await git.getViaGit(flavor, architecture)
+
+    // The `ucrt64` axis shares the `git-sdk-64` repository with
+    // `x86_64`, so the artifact name has to differ to keep caches and
+    // on-disk directories distinct.
+    expect(artifactName).toEqual('git-sdk-ucrt64-full')
+
+    await download(outputDirectory, true)
+
+    // The clone must target the `ucrt64` branch of `git-sdk-64`, not
+    // `main`, otherwise the wrong toolchain would be materialised.
+    expect(spawnSpy).toHaveBeenCalledWith(
+      expect.stringContaining('/git.exe'),
+      expect.arrayContaining([
+        'clone',
+        '--branch=ucrt64',
+        'https://github.com/git-for-windows/git-sdk-64'
+      ]),
+      expect.any(Object)
+    )
+  })
 })