diff --git a/services/github/check_suites/test_get_failed_check_runs.py b/services/github/check_suites/test_get_failed_check_runs.py
index 101010795..d9ea03b2d 100644
--- a/services/github/check_suites/test_get_failed_check_runs.py
+++ b/services/github/check_suites/test_get_failed_check_runs.py
@@ -1,15 +1,14 @@
 from unittest.mock import Mock, patch
 
 import requests
-from services.github.check_suites.get_failed_check_runs import \
-    get_failed_check_runs_from_check_suite
+from services.github.check_suites.get_failed_check_runs import (
+    get_failed_check_runs_from_check_suite,
+)
 
 
 @patch("services.github.check_suites.get_failed_check_runs.requests.get")
 @patch("services.github.check_suites.get_failed_check_runs.create_headers")
-def test_returns_failed_check_runs_when_mixed_outcomes(
-    mock_create_headers, mock_get
-):
+def test_returns_failed_check_runs_when_mixed_outcomes(mock_create_headers, mock_get):
     """Returns only failed check runs when suite includes failed and non-failed runs"""
     mock_create_headers.return_value = {"Authorization": "Bearer test-token"}
 
@@ -85,9 +84,7 @@ def test_returns_empty_when_no_failures(mock_create_headers, mock_get):
 @patch("services.github.check_suites.get_failed_check_runs.requests.get")
 @patch("services.github.check_suites.get_failed_check_runs.create_headers")
 @patch("builtins.print")
-def test_returns_empty_when_api_error(
-    mock_print, mock_create_headers, mock_get
-):
+def test_returns_empty_when_api_error(mock_print, mock_create_headers, mock_get):
     """Returns empty list when API returns error status code"""
     mock_create_headers.return_value = {"Authorization": "Bearer test-token"}
 
@@ -125,9 +122,7 @@ def test_returns_empty_when_not_found(mock_create_headers, mock_get):
 @patch("services.github.check_suites.get_failed_check_runs.requests.get")
 @patch("services.github.check_suites.get_failed_check_runs.create_headers")
 @patch("builtins.print")
-def test_returns_empty_when_unauthorized(
-    mock_print, mock_create_headers, mock_get
-):
+def test_returns_empty_when_unauthorized(mock_print, mock_create_headers, mock_get):
     """Returns empty list when authentication fails"""
     mock_create_headers.return_value = {"Authorization": "Bearer test-token"}
 
@@ -167,9 +162,7 @@ def test_returns_empty_when_response_has_no_check_runs_key(
 @patch("services.github.check_suites.get_failed_check_runs.requests.get")
 @patch("services.github.check_suites.get_failed_check_runs.create_headers")
 @patch("builtins.print")
-def test_returns_empty_when_forbidden(
-    mock_print, mock_create_headers, mock_get
-):
+def test_returns_empty_when_forbidden(mock_print, mock_create_headers, mock_get):
     """Returns empty list when access is forbidden"""
     mock_create_headers.return_value = {"Authorization": "Bearer test-token"}
 
@@ -188,9 +181,7 @@ def test_returns_empty_when_forbidden(
 
 @patch("services.github.check_suites.get_failed_check_runs.requests.get")
 @patch("services.github.check_suites.get_failed_check_runs.create_headers")
-def test_returns_empty_when_check_runs_array_is_empty(
-    mock_create_headers, mock_get
-):
+def test_returns_empty_when_check_runs_array_is_empty(mock_create_headers, mock_get):
     """Returns empty list when check_runs array is empty"""
     mock_create_headers.return_value = {"Authorization": "Bearer test-token"}
 
@@ -422,9 +413,7 @@ def test_returns_empty_when_json_parsing_fails(mock_create_headers, mock_get):
 
 @patch("services.github.check_suites.get_failed_check_runs.requests.get")
 @patch("services.github.check_suites.get_failed_check_runs.create_headers")
-def test_skips_check_runs_with_empty_string_conclusion(
-    mock_create_headers, mock_get
-):
+def test_skips_check_runs_with_empty_string_conclusion(mock_create_headers, mock_get):
     """Skips check runs with empty string as conclusion"""
     mock_create_headers.return_value = {"Authorization": "Bearer test-token"}
 
diff --git a/services/github/pulls/create_pull_request.py b/services/github/pulls/create_pull_request.py
index 4d86516bd..7452cf381 100644
--- a/services/github/pulls/create_pull_request.py
+++ b/services/github/pulls/create_pull_request.py
@@ -6,8 +6,8 @@
 from utils.error.handle_exceptions import handle_exceptions
 
 
-@handle_exceptions(default_return_value=None, raise_on_error=False)
-def create_pull_request(body: str, title: str, base_args: BaseArgs) -> str | None:
+@handle_exceptions(raise_on_error=True)
+def create_pull_request(body: str, title: str, base_args: BaseArgs):
     """https://docs.github.com/en/rest/pulls/pulls#create-a-pull-request"""
     owner, repo, base, head, token = (
         base_args["owner"],
@@ -24,13 +24,15 @@ def create_pull_request(body: str, title: str, base_args: BaseArgs) -> str | Non
     )
     if response.status_code == 422:
         msg = f"{create_pull_request.__name__} encountered an HTTPError: 422 Client Error: Unprocessable Entity for url: {response.url}, which is because no commits between the base branch and the working branch."
-        print(msg)
-        return None
+        raise requests.exceptions.HTTPError(msg)
+
     response.raise_for_status()
     pr_data = response.json()
+    pr_url: str = pr_data["html_url"]
+    pr_number: int = pr_data["number"]
 
     # Add reviewers to the pull request
-    base_args["pr_number"] = pr_data["number"]
+    base_args["pr_number"] = pr_number
     add_reviewers(base_args=base_args)
 
-    return pr_data["html_url"]
+    return pr_url, pr_number
diff --git a/services/github/pulls/test_create_pull_request.py b/services/github/pulls/test_create_pull_request.py
index c2383a162..196dcff4d 100644
--- a/services/github/pulls/test_create_pull_request.py
+++ b/services/github/pulls/test_create_pull_request.py
@@ -65,7 +65,7 @@ def test_create_pull_request_success(
 
     result = create_pull_request("Test body", "Test title", base_args)
 
-    assert result == "https://github.com/owner/repo/pull/123"
+    assert result == ("https://github.com/owner/repo/pull/123", 123)
     mock_post.assert_called_once_with(
         url="https://api.github.com/repos/gitautoai/gitauto/pulls",
         headers={"Authorization": "Bearer token"},
@@ -89,9 +89,7 @@ def test_create_pull_request_success(
 @patch("services.github.pulls.create_pull_request.add_reviewers")
 @patch("services.github.pulls.create_pull_request.create_headers")
 @patch("services.github.pulls.create_pull_request.requests.post")
-@patch("builtins.print")
 def test_create_pull_request_422_error(
-    mock_print,
     mock_post,
     mock_create_headers,
     mock_add_reviewers,
@@ -101,9 +99,14 @@ def test_create_pull_request_422_error(
     mock_post.return_value = mock_422_response
     mock_create_headers.return_value = {"Authorization": "Bearer token"}
 
-    result = create_pull_request("Test body", "Test title", base_args)
+    with pytest.raises(requests.exceptions.HTTPError) as exc_info:
+        create_pull_request("Test body", "Test title", base_args)
+
+    assert "422 Client Error: Unprocessable Entity" in str(exc_info.value)
+    assert "no commits between the base branch and the working branch" in str(
+        exc_info.value
+    )
 
-    assert result is None
     mock_post.assert_called_once_with(
         url="https://api.github.com/repos/gitautoai/gitauto/pulls",
         headers={"Authorization": "Bearer token"},
@@ -120,9 +123,6 @@ def test_create_pull_request_422_error(
     mock_422_response.json.assert_not_called()
     mock_add_reviewers.assert_not_called()
 
-    expected_msg = "create_pull_request encountered an HTTPError: 422 Client Error: Unprocessable Entity for url: https://api.github.com/repos/owner/repo/pulls, which is because no commits between the base branch and the working branch."
-    mock_print.assert_called_once_with(expected_msg)
-
 
 @patch("services.github.pulls.create_pull_request.add_reviewers")
 @patch("services.github.pulls.create_pull_request.create_headers")
@@ -137,9 +137,9 @@ def test_create_pull_request_http_error(
     mock_post.return_value = mock_error_response
     mock_create_headers.return_value = {"Authorization": "Bearer token"}
 
-    result = create_pull_request("Test body", "Test title", base_args)
+    with pytest.raises(requests.HTTPError):
+        create_pull_request("Test body", "Test title", base_args)
 
-    assert result is None
     mock_post.assert_called_once_with(
         url="https://api.github.com/repos/gitautoai/gitauto/pulls",
         headers={"Authorization": "Bearer token"},
@@ -171,9 +171,9 @@ def test_create_pull_request_json_error(
     mock_create_headers.return_value = {"Authorization": "Bearer token"}
     mock_response.json.side_effect = ValueError("Invalid JSON")
 
-    result = create_pull_request("Test body", "Test title", base_args)
+    with pytest.raises(ValueError):
+        create_pull_request("Test body", "Test title", base_args)
 
-    assert result is None
     mock_post.assert_called_once()
     mock_create_headers.assert_called_once_with(token="test-token-mock")
     mock_response.raise_for_status.assert_called_once()
@@ -195,9 +195,11 @@ def test_create_pull_request_add_reviewers_error(
     mock_create_headers.return_value = {"Authorization": "Bearer token"}
     mock_add_reviewers.side_effect = Exception("Reviewer error")
 
-    result = create_pull_request("Test body", "Test title", base_args)
+    with pytest.raises(Exception) as exc_info:
+        create_pull_request("Test body", "Test title", base_args)
+
+    assert "Reviewer error" in str(exc_info.value)
 
-    assert result is None
     mock_post.assert_called_once()
     mock_create_headers.assert_called_once_with(token="test-token-mock")
     mock_response.raise_for_status.assert_called_once()
@@ -219,7 +221,7 @@ def test_create_pull_request_empty_strings(
 
     result = create_pull_request("", "", base_args)
 
-    assert result == "https://github.com/owner/repo/pull/123"
+    assert result == ("https://github.com/owner/repo/pull/123", 123)
     mock_post.assert_called_once_with(
         url="https://api.github.com/repos/gitautoai/gitauto/pulls",
         headers={"Authorization": "Bearer token"},
@@ -245,7 +247,7 @@ def test_create_pull_request_different_branches(
 
     result = create_pull_request("Feature body", "Feature title", base_args)
 
-    assert result == "https://github.com/owner/repo/pull/123"
+    assert result == ("https://github.com/owner/repo/pull/123", 123)
     mock_post.assert_called_once_with(
         url="https://api.github.com/repos/gitautoai/gitauto/pulls",
         headers={"Authorization": "Bearer token"},
@@ -268,9 +270,9 @@ def test_create_pull_request_requests_exception(
     mock_post.side_effect = requests.RequestException("Network error")
     mock_create_headers.return_value = {"Authorization": "Bearer token"}
 
-    result = create_pull_request("Test body", "Test title", base_args)
+    with pytest.raises(requests.RequestException):
+        create_pull_request("Test body", "Test title", base_args)
 
-    assert result is None
     mock_post.assert_called_once()
     mock_create_headers.assert_called_once_with(token="test-token-mock")
     mock_add_reviewers.assert_not_called()
@@ -284,26 +286,13 @@ def test_create_pull_request_create_headers_exception(
 ):
     mock_create_headers.side_effect = Exception("Header creation error")
 
-    result = create_pull_request("Test body", "Test title", base_args)
+    with pytest.raises(Exception) as exc_info:
+        create_pull_request("Test body", "Test title", base_args)
+
+    assert "Header creation error" in str(exc_info.value)
 
-    assert result is None
     mock_create_headers.assert_called_once_with(token="test-token-mock")
     mock_post.assert_not_called()
     mock_add_reviewers.assert_not_called()
 
 
-@patch("services.github.pulls.create_pull_request.add_reviewers")
-@patch("services.github.pulls.create_pull_request.create_headers")
-@patch("services.github.pulls.create_pull_request.requests.post")
-def test_create_pull_request_key_error_in_base_args(
-    mock_post, mock_create_headers, mock_add_reviewers, test_owner, test_repo
-):
-    mock_create_headers.return_value = {"Authorization": "Bearer token"}
-    incomplete_base_args = {"owner": test_owner, "repo": test_repo}
-
-    result = create_pull_request("Test body", "Test title", incomplete_base_args)
-
-    assert result is None
-    mock_create_headers.assert_not_called()
-    mock_post.assert_not_called()
-    mock_add_reviewers.assert_not_called()
diff --git a/services/webhook/issue_handler.py b/services/webhook/issue_handler.py
index 4b2e0f795..0fa9bf95c 100644
--- a/services/webhook/issue_handler.py
+++ b/services/webhook/issue_handler.py
@@ -6,7 +6,7 @@
 from typing import Literal, cast
 
 # Local imports
-from config import PRODUCT_ID, PR_BODY_STARTS_WITH
+from config import GITHUB_API_URL, PRODUCT_ID, PR_BODY_STARTS_WITH
 from constants.messages import COMPLETED_PR, SETTINGS_LINKS
 from services.chat_with_agent import chat_with_agent
 from services.resend.send_email import send_email
@@ -25,15 +25,18 @@
 from services.github.commits.get_latest_remote_commit_sha import (
     get_latest_remote_commit_sha,
 )
+from services.github.commits.replace_remote_file import replace_remote_file_content
+from services.github.files.get_raw_content import get_raw_content
 from services.github.files.get_remote_file_content_by_url import (
     get_remote_file_content_by_url,
 )
 from services.github.markdown.render_text import render_text
 from services.github.pulls.create_pull_request import create_pull_request
+from services.github.pulls.get_pull_request_files import get_pull_request_files
 from services.github.reactions.add_reaction_to_issue import add_reaction_to_issue
 from services.github.types.github_types import GitHubLabeledPayload
-from services.jira.types import JiraPayload
 from services.github.utils.deconstruct_github_payload import deconstruct_github_payload
+from services.jira.types import JiraPayload
 
 # Local imports (Jira, OpenAI, Slack)
 from services.jira.deconstruct_jira_payload import deconstruct_jira_payload
@@ -53,16 +56,18 @@
 from services.supabase.owners.get_owner import get_owner
 
 # Local imports (Utils)
+from utils.files.is_test_file import is_test_file
+from utils.files.merge_test_file_headers import merge_test_file_headers
 from utils.images.get_base64 import get_base64
 from utils.progress_bar.progress_bar import create_progress_bar
-from utils.text.comment_identifiers import PROGRESS_BAR_FILLED, PROGRESS_BAR_EMPTY
+from utils.text.comment_identifiers import PROGRESS_BAR_EMPTY, PROGRESS_BAR_FILLED
 from utils.text.text_copy import (
     UPDATE_COMMENT_FOR_422,
     git_command,
     pull_request_completed,
 )
-from utils.time.is_lambda_timeout_approaching import is_lambda_timeout_approaching
 from utils.time.get_timeout_message import get_timeout_message
+from utils.time.is_lambda_timeout_approaching import is_lambda_timeout_approaching
 from utils.urls.extract_urls import extract_image_urls
 
 
@@ -355,16 +360,17 @@ def create_pr_from_issue(
 
     issue_link: str = f"{PR_BODY_STARTS_WITH}{issue_number}\n\n"
     pr_body = issue_link + git_command(new_branch_name=new_branch_name)
-    pr_url = create_pull_request(body=pr_body, title=issue_title, base_args=base_args)
+    pr_url, pr_number = create_pull_request(
+        body=pr_body, title=issue_title, base_args=base_args
+    )
 
-    if pr_url is not None:
-        comment_body = f"Created pull request: {pr_url}"
-        p += 5
-        log_messages.append(comment_body)
-        update_comment(
-            body=create_progress_bar(p=p, msg="\n".join(log_messages)),
-            base_args=base_args,
-        )
+    comment_body = f"Created pull request: {pr_url}"
+    p += 5
+    log_messages.append(comment_body)
+    update_comment(
+        body=create_progress_bar(p=p, msg="\n".join(log_messages)),
+        base_args=base_args,
+    )
 
     # Loop a process explore repo and commit changes until the ticket is resolved
     previous_calls = []
@@ -485,6 +491,37 @@ def create_pr_from_issue(
         # Because the agent is committing changes, keep doing the loop
         retry_count = 0
 
+    # Add headers to test files before triggering CI
+    files_url = (
+        f"{GITHUB_API_URL}/repos/{owner_name}/{repo_name}/pulls/{pr_number}/files"
+    )
+    changed_files = get_pull_request_files(url=files_url, token=token)
+
+    for file_change in changed_files:
+        file_path = file_change["filename"]
+        if not is_test_file(file_path):
+            continue
+
+        file_content = get_raw_content(
+            owner=owner_name,
+            repo=repo_name,
+            file_path=file_path,
+            ref=new_branch_name,
+            token=token,
+        )
+        if not file_content:
+            continue
+
+        updated_content = merge_test_file_headers(file_content, file_path)
+        if not updated_content or updated_content == file_content:
+            continue
+
+        replace_remote_file_content(
+            file_content=updated_content,
+            file_path=file_path,
+            base_args=base_args,
+        )
+
     # Trigger final test workflows with an empty commit
     comment_body = "Triggering workflows..."
     p += 5
@@ -494,31 +531,20 @@ def create_pr_from_issue(
     )
     create_empty_commit(base_args=base_args)
 
-    # Update the issue comment based on if the PR was created or not
-    pr_number = None
-    if pr_url is not None:
-        is_completed = True
-        pr_number = int(pr_url.split("/")[-1])
-        body_after_pr = pull_request_completed(
-            issuer_name=issuer_name,
-            sender_name=sender_name,
-            pr_url=pr_url,
-            is_automation=is_automation,
-        )
-
-        # Success notification
-        success_msg = f"Work completed for {owner_name}/{repo_name} PR: {pr_url}"
-        slack_notify(success_msg, thread_ts)
-    else:
-        is_completed = False
-        body_after_pr = UPDATE_COMMENT_FOR_422
-
-        # Failure notification
-        failure_msg = f"@channel Failed to create PR for {owner_name}/{repo_name}"
-        slack_notify(failure_msg, thread_ts)
-
+    # Update the issue comment
+    is_completed = True
+    body_after_pr = pull_request_completed(
+        issuer_name=issuer_name,
+        sender_name=sender_name,
+        pr_url=pr_url,
+        is_automation=is_automation,
+    )
     update_comment(body=body_after_pr, base_args=base_args)
 
+    # Success notification
+    success_msg = f"Work completed for {owner_name}/{repo_name} PR: {pr_url}"
+    slack_notify(success_msg, thread_ts)
+
     end_time = time.time()
     update_usage(
         usage_id=usage_id,
diff --git a/services/webhook/test_issue_handler.py b/services/webhook/test_issue_handler.py
index 349e5dc5e..0a0b248ef 100644
--- a/services/webhook/test_issue_handler.py
+++ b/services/webhook/test_issue_handler.py
@@ -164,7 +164,10 @@ def test_issue_handler_token_accumulation(
     mock_get_latest_remote_commit_sha.return_value = "abc123"
     mock_create_remote_branch.return_value = None
 
-    mock_create_pull_request.return_value = "https://github.com/test/repo/pull/123"
+    mock_create_pull_request.return_value = (
+        "https://github.com/test/repo/pull/123",
+        123,
+    )
     mock_create_empty_commit.return_value = None
     mock_check_branch_exists.return_value = True
     mock_insert_credit.return_value = None
diff --git a/utils/files/merge_test_file_headers.py b/utils/files/merge_test_file_headers.py
new file mode 100644
index 000000000..d6ac093b3
--- /dev/null
+++ b/utils/files/merge_test_file_headers.py
@@ -0,0 +1,110 @@
+import re
+from typing import TypedDict
+from utils.error.handle_exceptions import handle_exceptions
+from utils.files.is_test_file import is_test_file
+
+
+class LanguageConfig(TypedDict):
+    extensions: list[str]
+    rules: list[str]
+    pattern: str
+    format: str
+
+
+TEST_FILE_HEADERS: dict[str, LanguageConfig] = {
+    "typescript": {
+        "extensions": [".ts", ".tsx"],
+        "rules": [
+            "@typescript-eslint/no-unused-vars",
+            "@typescript-eslint/no-var-requires",
+        ],
+        "pattern": r"/\*\s*eslint-disable\s+([^*]+)\s*\*/",
+        "format": "/* eslint-disable {rules} */",
+    },
+    "javascript": {
+        "extensions": [".js", ".jsx"],
+        "rules": ["no-unused-vars"],
+        "pattern": r"/\*\s*eslint-disable\s+([^*]+)\s*\*/",
+        "format": "/* eslint-disable {rules} */",
+    },
+    "python": {
+        "extensions": [".py"],
+        "rules": ["redefined-outer-name", "unused-argument"],
+        "pattern": r"#\s*pylint:\s*disable=([^\n]+)",
+        "format": "# pylint: disable={rules}",
+    },
+    "php": {
+        "extensions": [".php"],
+        "rules": ["unused-variable"],
+        "pattern": r"//\s*phpcs:disable\s+([^\n]+)",
+        "format": "// phpcs:disable {rules}",
+    },
+}
+
+
+@handle_exceptions(default_return_value="", raise_on_error=False)
+def merge_test_file_headers(
+    file_content: str | None, file_path: str | None
+) -> str | None:
+    if not isinstance(file_content, str) or not isinstance(file_path, str):
+        return file_content
+
+    if not is_test_file(file_path):
+        return file_content
+
+    file_path_lower = file_path.lower()
+
+    config: LanguageConfig | None = None
+    for cfg in TEST_FILE_HEADERS.values():
+        for ext in cfg["extensions"]:
+            if file_path_lower.endswith(ext):
+                config = cfg
+                break
+        if config:
+            break
+
+    if not config:
+        return file_content
+
+    needed_rules = set(config["rules"])
+    existing_rules = set()
+
+    pattern = config["pattern"]
+    matches = list(re.finditer(pattern, file_content))
+
+    for match in matches:
+        rules_text = match.group(1).strip()
+        if "," in rules_text:
+            rules = [r.strip() for r in rules_text.split(",")]
+        else:
+            rules = [rules_text.strip()]
+
+        for rule in rules:
+            if rule:
+                existing_rules.add(rule)
+
+    missing_rules = needed_rules - existing_rules
+
+    if not missing_rules:
+        return file_content
+
+    all_rules = sorted(existing_rules | needed_rules)
+    rules_str = ", ".join(all_rules)
+    new_header = config["format"].format(rules=rules_str)
+
+    if matches:
+        content_without_comments = file_content
+        for match in reversed(matches):
+            end_pos = match.end()
+            if (
+                end_pos < len(content_without_comments)
+                and content_without_comments[end_pos] == "\n"
+            ):
+                end_pos += 1
+            content_without_comments = (
+                content_without_comments[: match.start()]
+                + content_without_comments[end_pos:]
+            )
+        content_without_comments = content_without_comments.lstrip()
+        return new_header + "\n" + content_without_comments
+    return new_header + "\n" + file_content
diff --git a/utils/files/test_merge_test_file_headers.py b/utils/files/test_merge_test_file_headers.py
new file mode 100644
index 000000000..ac4e4262f
--- /dev/null
+++ b/utils/files/test_merge_test_file_headers.py
@@ -0,0 +1,146 @@
+from utils.files.merge_test_file_headers import merge_test_file_headers
+
+
+def test_merge_test_file_headers_pattern1_no_ignore_lines():
+    file_content = """import { render } from '@testing-library/react';
+
+describe('Test', () => {});
+"""
+    result = merge_test_file_headers(file_content, "Component.test.tsx")
+    expected = """/* eslint-disable @typescript-eslint/no-unused-vars, @typescript-eslint/no-var-requires */
+import { render } from '@testing-library/react';
+
+describe('Test', () => {});
+"""
+    assert result == expected
+
+
+def test_merge_test_file_headers_pattern2_has_some_ignore_lines():
+    file_content = """/* eslint-disable no-console */
+import { render } from '@testing-library/react';
+
+describe('Test', () => {});
+"""
+    result = merge_test_file_headers(file_content, "Component.test.tsx")
+    expected = """/* eslint-disable @typescript-eslint/no-unused-vars, @typescript-eslint/no-var-requires, no-console */
+import { render } from '@testing-library/react';
+
+describe('Test', () => {});
+"""
+    assert result == expected
+
+
+def test_merge_test_file_headers_pattern3_already_has_exact_rules():
+    file_content = """/* eslint-disable @typescript-eslint/no-unused-vars, @typescript-eslint/no-var-requires */
+import { render } from '@testing-library/react';
+
+describe('Test', () => {});
+"""
+    result = merge_test_file_headers(file_content, "Component.test.tsx")
+    assert result == file_content
+
+
+def test_merge_test_file_headers_python():
+    file_content = """import pytest
+
+def test_function():
+    assert True
+"""
+    result = merge_test_file_headers(file_content, "test_module.py")
+    expected = """# pylint: disable=redefined-outer-name, unused-argument
+import pytest
+
+def test_function():
+    assert True
+"""
+    assert result == expected
+
+
+def test_merge_test_file_headers_comma_separated_existing():
+    file_content = """/* eslint-disable no-console, no-debugger */
+import { render } from '@testing-library/react';
+"""
+    result = merge_test_file_headers(file_content, "Component.test.tsx")
+    expected = """/* eslint-disable @typescript-eslint/no-unused-vars, @typescript-eslint/no-var-requires, no-console, no-debugger */
+import { render } from '@testing-library/react';
+"""
+    assert result == expected
+
+
+def test_merge_test_file_headers_non_test_file():
+    file_content = """import React from 'react';
+"""
+    result = merge_test_file_headers(file_content, "Component.tsx")
+    assert result == file_content
+
+
+def test_merge_test_file_headers_invalid_input():
+    result = merge_test_file_headers(None, "test.tsx")
+    assert result is None
+
+    result = merge_test_file_headers("content", None)
+    assert result == "content"
+
+
+def test_merge_test_file_headers_multiple_ignore_lines():
+    file_content = """/* eslint-disable no-console */
+import { render } from '@testing-library/react';
+/* eslint-disable no-debugger */
+
+describe('Test', () => {});
+"""
+    result = merge_test_file_headers(file_content, "Component.test.tsx")
+    expected = """/* eslint-disable @typescript-eslint/no-unused-vars, @typescript-eslint/no-var-requires, no-console, no-debugger */
+import { render } from '@testing-library/react';
+
+describe('Test', () => {});
+"""
+    assert result == expected
+
+
+def test_merge_test_file_headers_has_extra_rules():
+    file_content = """/* eslint-disable @typescript-eslint/no-unused-vars, @typescript-eslint/no-var-requires, no-console, no-debugger */
+import { render } from '@testing-library/react';
+
+describe('Test', () => {});
+"""
+    result = merge_test_file_headers(file_content, "Component.test.tsx")
+    assert result == file_content
+
+
+def test_merge_test_file_headers_javascript():
+    file_content = """const render = require('@testing-library/react').render;
+
+describe('Test', () => {});
+"""
+    result = merge_test_file_headers(file_content, "Component.test.js")
+    expected = """/* eslint-disable no-unused-vars */
+const render = require('@testing-library/react').render;
+
+describe('Test', () => {});
+"""
+    assert result == expected
+
+
+def test_merge_test_file_headers_php():
+    file_content = r"""<?php
+use PHPUnit\Framework\TestCase;
+
+class MyTest extends TestCase {
+    public function testSomething() {
+        $this->assertTrue(true);
+    }
+}
+"""
+    result = merge_test_file_headers(file_content, "MyTest.php")
+    expected = r"""// phpcs:disable unused-variable
+<?php
+use PHPUnit\Framework\TestCase;
+
+class MyTest extends TestCase {
+    public function testSomething() {
+        $this->assertTrue(true);
+    }
+}
+"""
+    assert result == expected