test: deterministic commit timestamps in test PRs

now that the remote helper uses the commit author timestamp to
determine if commit was applied from a proposal, the timestamps
in the test proposal can no longer be identical.

this makes them deterministically different based on the file name

4 files changed, 57 insertions, 11 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 819a249..51a7472 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3314,6 +3314,7 @@ dependencies = [
  "once_cell",
  "rand",
  "rexpect",
+ "sha2",
  "simple-websockets",
  "strip-ansi-escapes",
  "tokio",
diff --git a/test_utils/Cargo.toml b/test_utils/Cargo.toml
index 672dcdb..b354ff4 100644
--- a/test_utils/Cargo.toml
+++ b/test_utils/Cargo.toml
@@ -21,3 +21,4 @@ simple-websockets = { git = "https://github.com/DanConwayDev/simple-websockets",
 strip-ansi-escapes = "0.2.0"
 tokio = { version = "1.40.0", features = ["full"] }
 tungstenite = "0.20.1"
+sha2 = "0.10"
\ No newline at end of file
diff --git a/test_utils/src/lib.rs b/test_utils/src/lib.rs
index 0c5de73..3ac171b 100644
--- a/test_utils/src/lib.rs
+++ b/test_utils/src/lib.rs
@@ -10,6 +10,7 @@ use anyhow::{bail, ensure, Context, Result};
 use dialoguer::theme::{ColorfulTheme, Theme};
 use futures::executor::block_on;
 use git::GitTestRepo;
+use git2::{Signature, Time};
 use nostr::{self, nips::nip65::RelayMetadata, Kind, Tag};
 use nostr_database::NostrEventsDatabase;
 use nostr_lmdb::NostrLMDB;
@@ -1226,21 +1227,64 @@ pub fn create_and_populate_branch(
     test_repo.checkout("main")?;
     test_repo.create_branch(branch_name)?;
     test_repo.checkout(branch_name)?;
-    std::fs::write(
-        test_repo.dir.join(format!("{}3.md", prefix)),
-        "some content",
+    let file_name = format!("{}3.md", prefix);
+    std::fs::write(test_repo.dir.join(&file_name), "some content")?;
+    test_repo.stage_and_commit_custom_signature(
+        &format!("add {}3.md", prefix),
+        Some(
+            &Signature::new(
+                "Joe Bloggs",
+                "joe.bloggs@pm.me",
+                &Time::new(deterministic_timestamp(&file_name), 0),
+            )
+            .unwrap(),
+        ),
+        None,
     )?;
-    test_repo.stage_and_commit(format!("add {}3.md", prefix).as_str())?;
     if !only_one_commit {
-        std::fs::write(
-            test_repo.dir.join(format!("{}4.md", prefix)),
-            "some content",
+        let file_name = format!("{}4.md", prefix);
+        std::fs::write(test_repo.dir.join(&file_name), "some content")?;
+        test_repo.stage_and_commit_custom_signature(
+            &format!("add {}4.md", prefix),
+            Some(
+                &Signature::new(
+                    "Joe Bloggs",
+                    "joe.bloggs@pm.me",
+                    &Time::new(deterministic_timestamp(&file_name), 0),
+                )
+                .unwrap(),
+            ),
+            None,
         )?;
-        test_repo.stage_and_commit(format!("add {}4.md", prefix).as_str())?;
     }
     Ok(())
 }
 
+use sha2::{Digest, Sha256};
+
+fn deterministic_timestamp(input: &str) -> i64 {
+    // Create a SHA-256 hasher
+    let mut hasher = Sha256::new();
+
+    // Hash the input string
+    hasher.update(input);
+
+    // Get the hash result
+    let result = hasher.finalize();
+
+    // Convert the first 8 bytes of the hash to an i64
+    let timestamp_bytes = &result[..8];
+    let timestamp = i64::from_be_bytes(
+        timestamp_bytes
+            .try_into()
+            .expect("slice with incorrect length"),
+    );
+
+    // Normalize the timestamp to a valid Unix timestamp
+    // You can adjust this to fit your needs, e.g., adding a base timestamp
+    timestamp.abs() % 1_000_000_000 // Keep it within a reasonable range
+}
+
 pub fn cli_tester_create_proposal(
     test_repo: &GitTestRepo,
     branch_name: &str,
diff --git a/tests/git_remote_nostr/push.rs b/tests/git_remote_nostr/push.rs
index e5d1b13..a8ea0ac 100644
--- a/tests/git_remote_nostr/push.rs
+++ b/tests/git_remote_nostr/push.rs
@@ -1179,7 +1179,7 @@ async fn proposal_fast_forward_merge_commits_pushed_to_main_leads_to_status_even
         // HashSet::<String>::from_iter(vec![
         //     "merge-commit-id".to_string(),
         //     "6bd4f54bdf6a9ef2ec09e88e7a8d05376b0c1ff4".to_string(),
-        //     "eb5d67886abad23c259ebd684c2bba233f9ed3d1".to_string(),
+        //     "f1d302586abad23c259ebd684c2bba233f9ed3d1".to_string(),
         // ]),
         HashSet::from_iter(
             [
@@ -1292,7 +1292,7 @@ async fn push_2_commits_to_existing_proposal() -> Result<()> {
 
     assert_eq!(
         output,
-        format!("   eb5d678..7de5e41  {branch_name} -> {branch_name}\r\n").as_str(),
+        format!("   2d1b467..9d83ff4  {branch_name} -> {branch_name}\r\n").as_str(),
     );
 
     let new_events = r55
@@ -1447,7 +1447,7 @@ async fn force_push_creates_proposal_revision() -> Result<()> {
 
     assert_eq!(
         output,
-        format!(" + eb5d678...8a296c8 {branch_name} -> {branch_name} (forced update)\r\n").as_str(),
+        format!(" + 2d1b467...ead85e0 {branch_name} -> {branch_name} (forced update)\r\n").as_str(),
     );
 
     let new_events = r55