branch forget: error message if no globs match

src/commands/branch.rs

@@ -232,17 +232,36 @@ fn cmd_branch_forget(
     args: &BranchForgetArgs,
 ) -> Result<(), CommandError> {
     fn find_globs(view: &View, globs: &[String]) -> Result<Vec<String>, CommandError> {
-        let globs: Vec<glob::Pattern> = globs
+        let mut matching_branches: Vec<String> = vec![];
-            .iter()
+        let mut failed_globs = vec![];
-            .map(|glob| glob::Pattern::new(glob))
+        for glob_str in globs {
-            .try_collect()?;
+            let glob = glob::Pattern::new(glob_str)?;
-        let matching_branches = view
+            let names = view
                 .branches()
                 .iter()
                 .map(|(branch_name, _branch_target)| branch_name)
-            .filter(|branch_name| globs.iter().any(|glob| glob.matches(branch_name)))
+                .filter(|branch_name| glob.matches(branch_name))
                 .cloned()
-            .collect();
+                .collect_vec();
+            if names.is_empty() {
+                failed_globs.push(glob);
+            }
+            matching_branches.extend(names.into_iter());
+        }
+        match &failed_globs[..] {
+            [] => { /* No problem */ }
+            [glob] => {
+                return Err(user_error(format!(
+                    "The provided glob '{glob}' did not match any branches"
+                )))
+            }
+            globs => {
+                return Err(user_error(format!(
+                    "The provided globs '{}' did not match any branches",
+                    globs.iter().join("', '")
+                )))
+            }
+        };
         Ok(matching_branches)
     }
 

tests/test_branch_command.rs

@@ -112,6 +112,21 @@ fn test_branch_forget_glob() {
     insta::assert_snapshot!(stderr, @r###"
     Error: Failed to compile glob: Pattern syntax error near position 4: invalid range pattern
     "###);
+
+    // We get an error if none of the globs match anything
+    let stderr = test_env.jj_cmd_failure(
+        &repo_path,
+        &[
+            "branch",
+            "forget",
+            "--glob=bar*",
+            "--glob=baz*",
+            "--glob=boom*",
+        ],
+    );
+    insta::assert_snapshot!(stderr, @r###"
+    Error: The provided globs 'baz*', 'boom*' did not match any branches
+    "###);
 }
 
 #[test]