use libgit2 to track PRs (#10)v0.2.0

* nix: don't depend on registry for nixpkgs input

* use libgit2 to track PRs

* nix: don't use ci devShell as defaul

* crates: bump serenity from `9ad74d4` to `0.12.2

* nix: fix cross compiled builds

* crates: split more from client

* bot-jobs: update remote refs more efficiently

* git-tracker: account for HEAD commits

* bot-config: use nixpkgs branches from environment

* bot-commands: don't display branches prs haven't landed in

* git-tracker: return false when commits aren't found

this is annoying as a hard error since it turns out github will report
garbage merge commit SHAs for PRs that *haven't* been merged yet. yay

* bot: improve docs in some places

* bot-client: display invite link on start

* bot-http: add TeawieClientExt

* bot-commands: add /about

* docs: update readme todos

* nix: enable StateDirectory in module

* crates: bump to 0.2.0

1 files changed, 35 insertions, 0 deletions

diff --git a/crates/bot-http/src/github.rs b/crates/bot-http/src/github.rs
new file mode 100644
index 0000000..7822eb8
--- /dev/null
+++ b/crates/bot-http/src/github.rs
@@ -0,0 +1,35 @@
+use super::{ClientExt as _, Error};
+use crate::model::PullRequest;
+
+use std::future::Future;
+
+const GITHUB_API: &str = "https://api.github.com";
+
+pub trait ClientExt {
+	/// Get the commit that merged [`pr`] in [`repo_owner`]/[`repo_name`]
+	///
+	/// # Errors
+	///
+	/// Will return [`Err`] if the merge commit cannot be found
+	fn merge_commit_for(
+		&self,
+		repo_owner: &str,
+		repo_name: &str,
+		pr: u64,
+	) -> impl Future<Output = Result<Option<String>, Error>> + Send;
+}
+
+impl ClientExt for super::Client {
+	async fn merge_commit_for(
+		&self,
+		repo_owner: &str,
+		repo_name: &str,
+		pr: u64,
+	) -> Result<Option<String>, Error> {
+		let url = format!("{GITHUB_API}/repos/{repo_owner}/{repo_name}/pulls/{pr}");
+		let resp: PullRequest = self.get_json(&url).await?;
+		let merge_commit = resp.merge_commit_sha;
+
+		Ok(merge_commit)
+	}
+}