misc-helper get-pr-meta/get-pr-commits/handle-pr: prepare for git/git

To allow GitGitGadget to be used with PRs other than at
https://github.com/gitgitgadget/git, i.e. to support
https://github.com/git/git, let's teach these `misc-helper` commands
about (optionally) using a different repository.

This is a companion patch to the previous two, but unlike them, these
commands are not wired up in any active Azure Pipeline. Therefore, we
technically do not have to be careful to make the repository owner
optional. We still do because why not.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

script/misc-helper.ts

@@ -241,38 +241,47 @@ async function getCIHelper(): Promise<CIHelper> {
 
         console.log(toPrettyJSON(await ci.getMailMetadata(messageID)));
     } else if (command === "get-pr-meta") {
-        if (commander.args.length !== 2) {
-            process.stderr.write(`${command}: need a Pull Request number\n`);
+        if (commander.args.length !== 2 && commander.args.length !== 3) {
+            process.stderr.write(`${command}: need a repository owner and ${
+                                 ""}a Pull Request number\n`);
             process.exit(1);
         }
-        const prNumber = commander.args[1];
+        const repositoryOwner = commander.args.length === 3 ?
+            commander.args[1] : "gitgitgadget";
+        const prNumber = commander.args[commander.args.length === 3 ? 2 : 1];
 
         const pullRequestURL = prNumber.match(/^http/) ? prNumber :
-            `https://github.com/gitgitgadget/git/pull/${prNumber}`;
+            `https://github.com/${repositoryOwner}/git/pull/${prNumber}`;
         console.log(toPrettyJSON(await ci.getPRMetadata(pullRequestURL)));
     } else if (command === "get-pr-commits") {
-        if (commander.args.length !== 2) {
-            process.stderr.write(`${command}: need a Pull Request number\n`);
+        if (commander.args.length !== 2 && commander.args.length !== 3) {
+            process.stderr.write(`${command}: need a repository owner and ${
+                                 ""}a Pull Request number\n`);
             process.exit(1);
         }
-        const prNumber = commander.args[1];
+        const repositoryOwner = commander.args.length === 3 ?
+            commander.args[1] : "gitgitgadget";
+        const prNumber = commander.args[commander.args.length === 3 ? 2 : 1];
 
         const pullRequestURL =
-            `https://github.com/gitgitgadget/git/pull/${prNumber}`;
+            `https://github.com/${repositoryOwner}/git/pull/${prNumber}`;
         const prMeta = await ci.getPRMetadata(pullRequestURL);
         if (!prMeta) {
             throw new Error(`No metadata found for ${pullRequestURL}`);
         }
         console.log(toPrettyJSON(await ci.getOriginalCommitsForPR(prMeta)));
     } else if (command === "handle-pr") {
-        if (commander.args.length !== 2) {
-            process.stderr.write(`${command}: need a Pull Request number\n`);
+        if (commander.args.length !== 2 && commander.args.length !== 3) {
+            process.stderr.write(`${command}: need a repository owner and ${
+                                 ""}a Pull Request number\n`);
             process.exit(1);
         }
-        const prNumber = commander.args[1];
+        const repositoryOwner = commander.args.length === 3 ?
+            commander.args[1] : "gitgitgadget";
+        const prNumber = commander.args[commander.args.length === 3 ? 2 : 1];
 
         const pullRequestURL =
-            `https://github.com/gitgitgadget/git/pull/${prNumber}`;
+            `https://github.com/${repositoryOwner}/git/pull/${prNumber}`;
 
         const meta = await ci.getPRMetadata(pullRequestURL);
         if (!meta) {