feat: add diff ID support for PR file links

- Add SHA256 hash generation for file paths
- Update PR comment links to use proper diff anchors
- Add tests for the new functionality
- Update package version to 3.1.3

Author: villelahdenvuo

CHANGELOG.md

@@ -2,6 +2,13 @@
 
 # Changelog
 
+## [3.1.3] - 2026-01-14
+
+### Fixed
+
+- Fixed PR file links to use proper diff anchors instead of file path URLs,
+  keeping users in PR context and now including line numbers for precise navigation
+
 ## [3.1.2] - 2026-01-14
 
 ### Fixed

__tests__/main.test.ts

@@ -679,6 +679,17 @@ at Tests.Registration.main(Registration.java:202)`,
 		});
 	});
 
+	describe('getDiffId', () => {
+		it('should generate SHA256 hash for file path', () => {
+			expect(main.getDiffId('src/index.js')).toBe(
+				'bfe9874d239014961b1ae4e89875a6155667db834a410aaaa2ebe3cf89820556',
+			);
+			expect(main.getDiffId('src/modules/products/dto/product.dto.ts')).toBe(
+				'58d7002fa09097d6e54eec04b3ba865011f947ebb601513ede5829785248e69f',
+			);
+		});
+	});
+
 	describe('generateAnnotationSection', () => {
 		it('should return empty string for no annotations', () => {
 			expect(
@@ -707,7 +718,7 @@ at Tests.Registration.main(Registration.java:202)`,
 				'[.../modules/products/dto/product.dto.ts#L167]',
 			);
 			expect(result).toContain(
-				'(https://github.com/owner/repo/pull/123/files/src/modules/products/dto/product.dto.ts#L167)',
+				'(https://github.com/owner/repo/pull/123/files#diff-58d7002fa09097d6e54eec04b3ba865011f947ebb601513ede5829785248e69fR167)',
 			);
 		});
 

dist/index.js

@@ -1,7 +1,7 @@
 {
 	"name": "report-annotate",
 	"description": "Annotate PR from report e.g. junit",
-	"version": "3.1.2",
+	"version": "3.1.3",
 	"author": "",
 	"type": "module",
 	"private": true,

dist/index.js.map

@@ -2,6 +2,7 @@ import * as core from '@actions/core';
 import * as github from '@actions/github';
 import { existsSync } from 'node:fs';
 import { readFile } from 'node:fs/promises';
+import { createHash } from 'node:crypto';
 import { parse } from 'yaml';
 import { glob } from 'glob';
 import { junitEslintMatcher } from './matchers/junit-eslint.js';
@@ -379,6 +380,11 @@ export function truncateFilePath(filePath: string): string {
 	return '...' + '/' + parts.slice(-4).join('/');
 }
 
+/** Generate the diff ID for a file path in GitHub PR files view. */
+export function getDiffId(filePath: string): string {
+	return createHash('sha256').update(filePath).digest('hex');
+}
+
 /** Generate a comment section for a specific annotation level. */
 export function generateAnnotationSection(
 	levelName: string,
@@ -394,8 +400,8 @@ export function generateAnnotationSection(
 		let line = `> ${message}`;
 		if (annotation.properties.file && annotation.properties.startLine) {
 			const displayLocation = `${truncateFilePath(annotation.properties.file)}#L${annotation.properties.startLine}`;
-			const linkLocation = `${annotation.properties.file}#L${annotation.properties.startLine}`;
-			const link = `${baseUrl}/${linkLocation}`;
+			const diffId = getDiffId(annotation.properties.file);
+			const link = `${baseUrl}#diff-${diffId}R${annotation.properties.startLine}`;
 			line = `> [${displayLocation}](${link}) ${message}`;
 		}
 		section += `${line}\n`;