diff --git a/tests/specs/openai/diff-fixtures/README.md b/tests/fixtures/README.md
similarity index 100%
rename from tests/specs/openai/diff-fixtures/README.md
rename to tests/fixtures/README.md
diff --git a/tests/specs/openai/diff-fixtures/chore.txt b/tests/fixtures/chore.diff
similarity index 100%
rename from tests/specs/openai/diff-fixtures/chore.txt
rename to tests/fixtures/chore.diff
diff --git a/tests/specs/openai/diff-fixtures/code-refactoring.txt b/tests/fixtures/code-refactoring.diff
similarity index 100%
rename from tests/specs/openai/diff-fixtures/code-refactoring.txt
rename to tests/fixtures/code-refactoring.diff
diff --git a/tests/specs/openai/diff-fixtures/code-style.txt b/tests/fixtures/code-style.diff
similarity index 100%
rename from tests/specs/openai/diff-fixtures/code-style.txt
rename to tests/fixtures/code-style.diff
diff --git a/tests/specs/openai/diff-fixtures/continous-integration.txt b/tests/fixtures/continous-integration.diff
similarity index 100%
rename from tests/specs/openai/diff-fixtures/continous-integration.txt
rename to tests/fixtures/continous-integration.diff
diff --git a/tests/specs/openai/diff-fixtures/deprecate-feature.txt b/tests/fixtures/deprecate-feature.diff
similarity index 100%
rename from tests/specs/openai/diff-fixtures/deprecate-feature.txt
rename to tests/fixtures/deprecate-feature.diff
diff --git a/tests/specs/openai/diff-fixtures/documentation-changes.txt b/tests/fixtures/documentation-changes.diff
similarity index 100%
rename from tests/specs/openai/diff-fixtures/documentation-changes.txt
rename to tests/fixtures/documentation-changes.diff
diff --git a/tests/specs/openai/diff-fixtures/fix-nullpointer-exception.txt b/tests/fixtures/fix-nullpointer-exception.diff
similarity index 100%
rename from tests/specs/openai/diff-fixtures/fix-nullpointer-exception.txt
rename to tests/fixtures/fix-nullpointer-exception.diff
diff --git a/tests/specs/openai/diff-fixtures/github-action-build-pipeline.txt b/tests/fixtures/github-action-build-pipeline.diff
similarity index 100%
rename from tests/specs/openai/diff-fixtures/github-action-build-pipeline.txt
rename to tests/fixtures/github-action-build-pipeline.diff
diff --git a/tests/specs/openai/diff-fixtures/new-feature.txt b/tests/fixtures/new-feature.diff
similarity index 100%
rename from tests/specs/openai/diff-fixtures/new-feature.txt
rename to tests/fixtures/new-feature.diff
diff --git a/tests/specs/openai/diff-fixtures/performance-improvement.txt b/tests/fixtures/performance-improvement.diff
similarity index 100%
rename from tests/specs/openai/diff-fixtures/performance-improvement.txt
rename to tests/fixtures/performance-improvement.diff
diff --git a/tests/specs/openai/diff-fixtures/remove-feature.txt b/tests/fixtures/remove-feature.diff
similarity index 100%
rename from tests/specs/openai/diff-fixtures/remove-feature.txt
rename to tests/fixtures/remove-feature.diff
diff --git a/tests/specs/openai/diff-fixtures/testing-react-application.txt b/tests/fixtures/testing-react-application.diff
similarity index 100%
rename from tests/specs/openai/diff-fixtures/testing-react-application.txt
rename to tests/fixtures/testing-react-application.diff
diff --git a/tests/specs/openai/conventional-commits.ts b/tests/specs/openai/conventional-commits.ts
index 1fd537ee..b89255eb 100644
--- a/tests/specs/openai/conventional-commits.ts
+++ b/tests/specs/openai/conventional-commits.ts
@@ -1,11 +1,9 @@
-import { readFile } from 'fs/promises';
-import path from 'path';
-import { fileURLToPath } from 'url';
 import { expect, testSuite } from 'manten';
 import {
 	generateCommitMessage,
 } from '../../../src/utils/openai.js';
 import type { ValidConfig } from '../../../src/utils/config.js';
+import { getDiff } from '../../utils.js';
 
 const { OPENAI_KEY } = process.env;
 
@@ -19,7 +17,7 @@ export default testSuite(({ describe }) => {
 		await test('Should not translate conventional commit type to Japanase when locale config is set to japanese', async () => {
 			const japaneseConventionalCommitPattern = /(build|chore|ci|docs|feat|fix|perf|refactor|revert|style|test)(\(.*\))?: [\u3000-\u303F\u3040-\u309F\u30A0-\u30FF\uFF00-\uFF9F\u4E00-\u9FAF\u3400-\u4DBF]/;
 
-			const gitDiff = await readDiffFromFile('new-feature.txt');
+			const gitDiff = await getDiff('new-feature.diff');
 
 			const commitMessage = await runGenerateCommitMessage(gitDiff, {
 				locale: 'ja',
@@ -30,7 +28,7 @@ export default testSuite(({ describe }) => {
 		});
 
 		await test('Should use "feat:" conventional commit when change relate to adding a new feature', async () => {
-			const gitDiff = await readDiffFromFile('new-feature.txt');
+			const gitDiff = await getDiff('new-feature.diff');
 
 			const commitMessage = await runGenerateCommitMessage(gitDiff);
 
@@ -40,7 +38,7 @@ export default testSuite(({ describe }) => {
 		});
 
 		await test('Should use "refactor:" conventional commit when change relate to code refactoring', async () => {
-			const gitDiff = await readDiffFromFile('code-refactoring.txt');
+			const gitDiff = await getDiff('code-refactoring.diff');
 
 			const commitMessage = await runGenerateCommitMessage(gitDiff);
 
@@ -50,7 +48,7 @@ export default testSuite(({ describe }) => {
 		});
 
 		await test('Should use "test:" conventional commit when change relate to testing a React application', async () => {
-			const gitDiff = await readDiffFromFile('testing-react-application.txt');
+			const gitDiff = await getDiff('testing-react-application.diff');
 
 			const commitMessage = await runGenerateCommitMessage(gitDiff);
 
@@ -60,8 +58,8 @@ export default testSuite(({ describe }) => {
 		});
 
 		await test('Should use "build:" conventional commit when change relate to github action build pipeline', async () => {
-			const gitDiff = await readDiffFromFile(
-				'github-action-build-pipeline.txt',
+			const gitDiff = await getDiff(
+				'github-action-build-pipeline.diff',
 			);
 
 			const commitMessage = await runGenerateCommitMessage(gitDiff);
@@ -72,7 +70,7 @@ export default testSuite(({ describe }) => {
 		});
 
 		await test('Should use "(ci|build):" conventional commit when change relate to continious integration', async () => {
-			const gitDiff = await readDiffFromFile('continous-integration.txt');
+			const gitDiff = await getDiff('continous-integration.diff');
 
 			const commitMessage = await runGenerateCommitMessage(gitDiff);
 
@@ -83,7 +81,7 @@ export default testSuite(({ describe }) => {
 		});
 
 		await test('Should use "docs:" conventional commit when change relate to documentation changes', async () => {
-			const gitDiff = await readDiffFromFile('documentation-changes.txt');
+			const gitDiff = await getDiff('documentation-changes.diff');
 			const commitMessage = await runGenerateCommitMessage(gitDiff);
 
 			// should match "docs:" or "docs(<scope>):"
@@ -92,7 +90,7 @@ export default testSuite(({ describe }) => {
 		});
 
 		await test('Should use "fix:" conventional commit when change relate to fixing code', async () => {
-			const gitDiff = await readDiffFromFile('fix-nullpointer-exception.txt');
+			const gitDiff = await getDiff('fix-nullpointer-exception.diff');
 			const commitMessage = await runGenerateCommitMessage(gitDiff);
 
 			// should match "fix:" or "fix(<scope>):"
@@ -102,7 +100,7 @@ export default testSuite(({ describe }) => {
 		});
 
 		await test('Should use "style:" conventional commit when change relate to code style improvements', async () => {
-			const gitDiff = await readDiffFromFile('code-style.txt');
+			const gitDiff = await getDiff('code-style.diff');
 			const commitMessage = await runGenerateCommitMessage(gitDiff);
 
 			// should match "style:" or "style(<style>):"
@@ -111,7 +109,7 @@ export default testSuite(({ describe }) => {
 		});
 
 		await test('Should use "chore:" conventional commit when change relate to a chore or maintenance', async () => {
-			const gitDiff = await readDiffFromFile('chore.txt');
+			const gitDiff = await getDiff('chore.diff');
 			const commitMessage = await runGenerateCommitMessage(gitDiff);
 
 			// should match "chore:" or "chore(<style>):"
@@ -121,7 +119,7 @@ export default testSuite(({ describe }) => {
 		});
 
 		await test('Should use "perf:" conventional commit when change relate to a performance improvement', async () => {
-			const gitDiff = await readDiffFromFile('performance-improvement.txt');
+			const gitDiff = await getDiff('performance-improvement.diff');
 			const commitMessage = await runGenerateCommitMessage(gitDiff);
 
 			// should match "perf:" or "perf(<style>):"
@@ -143,19 +141,5 @@ export default testSuite(({ describe }) => {
 
 			return commitMessages[0];
 		}
-
-		/*
-		 *	See ./diffs/README.md in order to generate diff files
-		 */
-		async function readDiffFromFile(filename: string): Promise<string> {
-			const __filename = fileURLToPath(import.meta.url);
-			const __dirname = path.dirname(__filename);
-			const gitDiff = await readFile(
-				path.resolve(__dirname, `./diff-fixtures/${filename}`),
-				'utf8',
-			);
-
-			return gitDiff;
-		}
 	});
 });
diff --git a/tests/utils.ts b/tests/utils.ts
index 2359141b..8bf3d1ab 100644
--- a/tests/utils.ts
+++ b/tests/utils.ts
@@ -1,4 +1,5 @@
 import path from 'path';
+import fs from 'fs/promises';
 import { execa, execaNode, type Options } from 'execa';
 import {
 	createFixture as createFixtureBase,
@@ -83,3 +84,9 @@ export const assertOpenAiToken = () => {
 		throw new Error('⚠️  process.env.OPENAI_KEY is necessary to run these tests. Skipping...');
 	}
 };
+
+// See ./diffs/README.md in order to generate diff files
+export const getDiff = async (diffName: string): Promise<string> => fs.readFile(
+	new URL(`fixtures/${diffName}`, import.meta.url),
+	'utf8',
+);