test: fix vacuous is_err() assertions in create_git_tag and comment_on_work_item

src/safe_outputs/comment_on_work_item.rs

@@ -387,7 +387,11 @@ mod tests {
             body: "This is a valid comment body text.".to_string(),
         };
         let result: Result<CommentOnWorkItemResult, _> = params.try_into();
-        assert!(result.is_err());
+        let err = result.unwrap_err().to_string();
+        assert!(
+            err.contains("work_item_id must be positive"),
+            "unexpected error: {err}"
+        );
     }
 
     #[test]
@@ -397,7 +401,11 @@ mod tests {
             body: "This is a valid comment body text.".to_string(),
         };
         let result: Result<CommentOnWorkItemResult, _> = params.try_into();
-        assert!(result.is_err());
+        let err = result.unwrap_err().to_string();
+        assert!(
+            err.contains("work_item_id must be positive"),
+            "unexpected error: {err}"
+        );
     }
 
     #[test]
@@ -407,7 +415,11 @@ mod tests {
             body: "Too short".to_string(),
         };
         let result: Result<CommentOnWorkItemResult, _> = params.try_into();
-        assert!(result.is_err());
+        let err = result.unwrap_err().to_string();
+        assert!(
+            err.contains("body must be at least 10 characters"),
+            "unexpected error: {err}"
+        );
     }
 
     #[test]

src/safe_outputs/create_git_tag.rs

@@ -463,7 +463,11 @@ mod tests {
             repository: None,
         };
         let result: Result<CreateGitTagResult, _> = params.try_into();
-        assert!(result.is_err());
+        let err = result.unwrap_err().to_string();
+        assert!(
+            err.contains("message must be at least 5 characters"),
+            "unexpected error: {err}"
+        );
     }
 
     #[test]
@@ -475,7 +479,11 @@ mod tests {
             repository: Some("##vso[task.setvariable variable=x]y".to_string()),
         };
         let result: Result<CreateGitTagResult, _> = params.try_into();
-        assert!(result.is_err());
+        let err = result.unwrap_err().to_string();
+        assert!(
+            err.contains("pipeline command"),
+            "unexpected error: {err}"
+        );
     }
 
     #[test]