gatewayd: approvals, the registry and the judging of commands

Implemented-By: OpenCode session (model recorded in docs/implementer-log.md)

crates/gatewayd/tests/approvals_judge.rs

@@ -0,0 +1,166 @@
+//! Which commands answer an approval, in the order of the M4b spec, section 7; everything else is
+//! answered with its reason and changes nothing. Do not edit.
+
+use std::sync::mpsc::{self, Receiver};
+
+use gatewayd::approvals::{Judged, NOT_APPROVER, Posted, Registry, USAGE};
+use gatewayd::sessions::ApprovalCommand::{self, Approve, Deny, Malformed};
+use proto::ApprovalReply;
+
+const KYLE: &str = "k0000000000000000000000000";
+const HERMES: &str = "h0000000000000000000000000";
+const DM: &str = "d0000000000000000000000000";
+const ROOT: &str = "r0000000000000000000000000";
+const ELSEWHERE: &str = "e0000000000000000000000000";
+const CMD: &str = "c0000000000000000000000001";
+
+fn approvers() -> Vec<String> {
+    vec![KYLE.to_string()]
+}
+
+/// A registry with approval 42 posted in ROOT, shown at 100.
+fn posted(answerable: bool) -> (Registry, Receiver<ApprovalReply>) {
+    let registry = Registry::new();
+    let (tx, rx) = mpsc::channel();
+    registry.add(Posted {
+        approval: 42,
+        session: format!("mm-{ROOT}"),
+        channel: DM.to_string(),
+        root: ROOT.to_string(),
+        shown_at: 100,
+        answerable,
+        answer: tx,
+    });
+    (registry, rx)
+}
+
+fn judge(r: &Registry, command: &ApprovalCommand, user: &str, root: &str, at: i64) -> Judged {
+    r.judge(command, user, root, CMD, at, &approvers())
+}
+
+#[test]
+fn an_approver_in_the_thread_after_the_post_answers_it() {
+    let (r, rx) = posted(true);
+    assert_eq!(judge(&r, &Approve(42), KYLE, ROOT, 101), Judged::Sent);
+    assert_eq!(
+        rx.try_recv().unwrap(),
+        ApprovalReply {
+            approval: 42,
+            approved: true,
+            by: KYLE.to_string(),
+            post: CMD.to_string(),
+            reason: None
+        }
+    );
+    assert!(!r.holds(42), "answered once");
+    assert_eq!(
+        judge(&r, &Approve(42), KYLE, ROOT, 102),
+        Judged::Reply("approval 42 is not pending here".to_string())
+    );
+    assert!(rx.try_recv().is_err(), "a second answer goes nowhere");
+}
+
+#[test]
+fn a_refusal_carries_its_reason() {
+    let (r, rx) = posted(true);
+    assert_eq!(
+        judge(
+            &r,
+            &Deny(42, Some("not on a Friday".to_string())),
+            KYLE,
+            ROOT,
+            101
+        ),
+        Judged::Sent
+    );
+    let got = rx.try_recv().unwrap();
+    assert_eq!(
+        (got.approved, got.reason.as_deref()),
+        (false, Some("not on a Friday"))
+    );
+    let (r, rx) = posted(true);
+    assert_eq!(judge(&r, &Deny(42, None), KYLE, ROOT, 101), Judged::Sent);
+    assert_eq!(rx.try_recv().unwrap().reason, None);
+}
+
+#[test]
+fn everything_else_is_refused_with_its_reason_in_order() {
+    let cases: &[(&ApprovalCommand, &str, &str, i64, &str)] = &[
+        (&Approve(42), HERMES, ROOT, 101, NOT_APPROVER),
+        (&Malformed, HERMES, ROOT, 101, NOT_APPROVER),
+        (&Malformed, KYLE, ROOT, 101, USAGE),
+        (
+            &Approve(7),
+            KYLE,
+            ROOT,
+            101,
+            "approval 7 is not pending here",
+        ),
+        (
+            &Approve(42),
+            KYLE,
+            ELSEWHERE,
+            101,
+            "approval 42 is answered in its own thread",
+        ),
+        (
+            &Approve(42),
+            KYLE,
+            ROOT,
+            100,
+            "approval 42 was answered before it was shown in full",
+        ),
+        (
+            &Approve(42),
+            KYLE,
+            ROOT,
+            50,
+            "approval 42 was answered before it was shown in full",
+        ),
+        (
+            &Approve(42),
+            KYLE,
+            ELSEWHERE,
+            50,
+            "approval 42 is answered in its own thread",
+        ),
+    ];
+    for (command, user, root, at, want) in cases {
+        let (r, rx) = posted(true);
+        assert_eq!(
+            judge(&r, command, user, root, *at),
+            Judged::Reply(want.to_string()),
+            "{command:?} {user} {root} {at}"
+        );
+        assert!(r.holds(42), "still pending after {command:?}");
+        assert!(rx.try_recv().is_err(), "nothing sent for {command:?}");
+    }
+}
+
+#[test]
+fn too_long_to_show_is_answered_only_in_bxctl() {
+    let (r, rx) = posted(false);
+    assert_eq!(
+        judge(&r, &Approve(42), KYLE, ROOT, 101),
+        Judged::Reply("approval 42 can only be answered with bxctl approvals".to_string())
+    );
+    assert!(r.holds(42) && rx.try_recv().is_err());
+}
+
+#[test]
+fn an_answer_whose_connection_is_gone_is_not_pending() {
+    let (r, rx) = posted(true);
+    drop(rx);
+    assert_eq!(
+        judge(&r, &Approve(42), KYLE, ROOT, 101),
+        Judged::Reply("approval 42 is not pending here".to_string())
+    );
+}
+
+#[test]
+fn the_waiting_sessions_and_removal() {
+    let (r, _rx) = posted(true);
+    assert_eq!(r.waiting_sessions(), [format!("mm-{ROOT}")]);
+    assert_eq!(r.remove(42).map(|p| p.approval), Some(42));
+    assert!(r.waiting_sessions().is_empty() && !r.holds(42) && r.remove(42).is_none());
+}