test(e2e): retry the sha lookup in apiUpdateFile

The update API needs the current blob sha, but the GET fetching it was
neither retried nor status-checked: a transient 5xx or a 404 surfaced as
a confusing JSON parse error instead of the retry helper's message.
Wrap it like apiCreatePR does, reading the sha only when the response
is ok.

Assisted-by: Codet

Author: lunny

tests/e2e/utils.ts

@@ -89,10 +89,14 @@ export async function apiCreateFile(requestContext: APIRequestContext, owner: st
 
 /** Update an existing file's content on a branch (fetches the current blob sha first, as the update API requires it). */
 export async function apiUpdateFile(requestContext: APIRequestContext, owner: string, repo: string, filepath: string, content: string, {branch, message}: {branch?: string; message?: string} = {}) {
-  const getResponse = await requestContext.get(`${baseUrl()}/api/v1/repos/${owner}/${repo}/contents/${filepath}${branch ? `?ref=${encodeURIComponent(branch)}` : ''}`, {
-    headers: apiHeaders(),
-  });
-  const {sha} = await getResponse.json();
+  let sha = '';
+  await apiRetry(async () => {
+    const response = await requestContext.get(`${baseUrl()}/api/v1/repos/${owner}/${repo}/contents/${filepath}${branch ? `?ref=${encodeURIComponent(branch)}` : ''}`, {
+      headers: apiHeaders(),
+    });
+    if (response.ok()) sha = (await response.json()).sha;
+    return response;
+  }, 'apiUpdateFile:getSha');
   await apiRetry(() => requestContext.put(`${baseUrl()}/api/v1/repos/${owner}/${repo}/contents/${filepath}`, {
     headers: apiHeaders(),
     data: {content: Buffer.from(content, 'utf8').toString('base64'), sha, branch, message},