Read github credentials from git credential helper

revup/git.py

@@ -808,3 +808,38 @@ async def soft_reset(self, new_commit: GitCommitHash, env: Dict) -> None:
 
         # TODO: only strictly needs to drop entries for HEAD
         self.clear_cache()
+
+    async def credential(self, **kwargs: Dict[str, str]) -> str:
+        cred = Credential(self, description=kwargs)
+        await cred.fill()
+        return cred.password
+
+
+class Credential():
+    git_ctx: Git
+    description: Dict[str, str]
+
+    def __init__(self, git: Git, description: Dict[str, str]):
+        self.git_ctx = git
+        self.description = description
+
+    def __getattr__(self, attr):
+        return self.description[attr]
+
+    async def _run(self, subcommand, input: Dict[str, str]) -> Dict[str, str]:
+        input_str = "\n".join(f"{k}={v}" for k, v in input.items())
+        stdout_str = await self.git_ctx.git_stdout("credential", subcommand, input_str=input_str)
+        stdout = {}
+        for line in stdout_str.splitlines():
+            if line == "":
+                break
+            k, v = line.split("=", 1)
+            stdout[k] = v
+        return stdout
+
+    async def fill(self):
+        self.description = await self._run("fill", self.description)
+
+    async def report(self, success: bool):
+        cmd = "approve" if success else "reject"
+        await self._run(cmd, self.description)

revup/revup.py

@@ -199,6 +199,13 @@ async def github_connection(
             f"the same repo as the remote {args.remote_info}."
         )
 
+    if not args.github_oauth:
+        args.github_oauth = await git_ctx.credential(
+            protocol="https",
+            host=args.github_url,
+            path=f"/{fork_info.owner}/{fork_info.name}.git",
+        )
+
     if not args.github_oauth:
         raise RevupUsageException(
             "No Github OAuth token configured! "