Reuse code, do not update Mergeable Check unnecessary

tests/ci/commit_status_helper.py

@@ -3,7 +3,7 @@
 import csv
 import os
 import time
-from typing import List
+from typing import List, Literal
 import logging
 
 from ci_config import CI_CONFIG, REQUIRED_CHECKS
@@ -15,6 +15,7 @@ from pr_info import PRInfo, SKIP_MERGEABLE_CHECK_LABEL
 
 RETRY = 5
 CommitStatuses = List[CommitStatus]
+MERGEABLE_NAME = "Mergeable Check"
 
 
 def override_status(status: str, check_name: str, invert: bool = False) -> str:
@@ -102,26 +103,21 @@ def post_labels(gh: Github, pr_info: PRInfo, labels_names: List[str]) -> None:
         pull_request.add_to_labels(label)
 
 
-def fail_mergeable_check(commit: Commit, description: str) -> None:
-    commit.create_status(
-        context="Mergeable Check",
-        description=description,
-        state="failure",
-        target_url=GITHUB_RUN_URL,
-    )
-
-
 def format_description(description: str) -> str:
     if len(description) > 140:
         description = description[:137] + "..."
     return description
 
 
-def reset_mergeable_check(commit: Commit, description: str = "") -> None:
+def set_mergeable_check(
+    commit: Commit,
+    description: str = "",
+    state: Literal["success", "failure"] = "success",
+) -> None:
     commit.create_status(
-        context="Mergeable Check",
+        context=MERGEABLE_NAME,
         description=description,
-        state="success",
+        state=state,
         target_url=GITHUB_RUN_URL,
     )
 
@@ -133,32 +129,39 @@ def update_mergeable_check(gh: Github, pr_info: PRInfo, check_name: str) -> None
     logging.info("Update Mergeable Check by %s", check_name)
 
     commit = get_commit(gh, pr_info.sha)
-    checks = {
-        check.context: check.state
-        for check in filter(
-            lambda check: (check.context in REQUIRED_CHECKS),
-            # get_statuses() returns generator, which cannot be reversed - we need comprehension
-            # pylint: disable=unnecessary-comprehension
-            reversed([status for status in commit.get_statuses()]),
-        )
-    }
+    statuses = get_commit_filtered_statuses(commit)
+
+    required_checks = [
+        status for status in statuses if status.context in REQUIRED_CHECKS
+    ]
+
+    mergeable_status = None
+    for status in statuses:
+        if status.context == MERGEABLE_NAME:
+            mergeable_status = status
+            break
 
     success = []
     fail = []
-    for name, state in checks.items():
-        if state == "success":
-            success.append(name)
+    for status in required_checks:
+        if status.state == "success":
+            success.append(status.context)
         else:
-            fail.append(name)
+            fail.append(status.context)
 
     if fail:
         description = "failed: " + ", ".join(fail)
         if success:
             description += "; succeeded: " + ", ".join(success)
         description = format_description(description)
-        fail_mergeable_check(commit, description)
+        if mergeable_status is not None and mergeable_status.description == description:
+            return
+        set_mergeable_check(commit, description, "failure")
         return
 
     description = ", ".join(success)
     description = format_description(description)
-    reset_mergeable_check(commit, description)
+    if mergeable_status is not None and mergeable_status.description == description:
+        return
+
+    set_mergeable_check(commit, description)

tests/ci/run_check.py

@@ -11,7 +11,7 @@ from commit_status_helper import (
     get_commit,
     post_labels,
     remove_labels,
-    reset_mergeable_check,
+    set_mergeable_check,
 )
 from env_helper import GITHUB_RUN_URL, GITHUB_REPOSITORY, GITHUB_SERVER_URL
 from get_robot_token import get_best_robot_token
@@ -232,7 +232,7 @@ if __name__ == "__main__":
     if pr_labels_to_remove:
         remove_labels(gh, pr_info, pr_labels_to_remove)
 
-    reset_mergeable_check(commit, "skipped")
+    set_mergeable_check(commit, "skipped")
 
     if description_error:
         print(