diff --git a/bun.lockb b/bun.lockb
index c5df9fd..7fe6a9b 100755
Binary files a/bun.lockb and b/bun.lockb differ
diff --git a/package.json b/package.json
index 05bf4e5..9ee928f 100644
--- a/package.json
+++ b/package.json
@@ -87,7 +87,9 @@
     "@rollup/plugin-commonjs": "^28.0.2",
     "@rollup/plugin-node-resolve": "^16.0.0",
     "@types/express": "^5.0.0",
+    "@types/jest": "^30.0.0",
     "@types/js-yaml": "^4.0.9",
+    "@types/mocha": "^10.0.10",
     "@types/node": "^22.13.4",
     "@types/nodemailer": "^6.4.17",
     "@types/nodemailer-express-handlebars": "^4.0.5",
diff --git a/src/configs/app.config.ts b/src/configs/app.config.ts
index 2bfaeb6..7c5fbe8 100644
--- a/src/configs/app.config.ts
+++ b/src/configs/app.config.ts
@@ -2,7 +2,6 @@ export const appConfig = {
   drGitApiKeyName: 'DR_GIT_API_KEY',
   configFileNames: ['.drgit.yml', '.drgit.yaml'],
   metadata: {
-    // Don't change these strings on production
     walkthrough: '[drgit]: walkthrough',
     diagram: '[drgit]: diagram',
     summary: '[drgit]: summary'
diff --git a/src/handlers/app.handler.ts b/src/handlers/app.handler.ts
index 3b179df..c654c94 100644
--- a/src/handlers/app.handler.ts
+++ b/src/handlers/app.handler.ts
@@ -88,7 +88,7 @@ export class AppHandler {
     new UserErrorListener().listen();
 
     if (envs.isDevelopment) {
-      await this.services.cacheService.flush();
+      await this.services.cacheService.flushByPattern('user/*');
 
       systemLogger.info('Cache has been flushed');
     }
@@ -103,6 +103,7 @@ export class AppHandler {
       config = await this.services.configService.getConfig(context, apiKey);
 
       await this.services.appService.init(context);
+      if (!apiKey || !config) return;
       await callback(apiKey, config);
     } catch (error) {
       if ('repository' in context.payload) {
diff --git a/src/services/cache.service.ts b/src/services/cache.service.ts
index 3939f43..748e341 100644
--- a/src/services/cache.service.ts
+++ b/src/services/cache.service.ts
@@ -103,6 +103,18 @@ export class CacheService<Key extends string = CacheKey> {
     });
   }
 
+  async flushByPattern(pattern: string): Promise<number> {
+    return this.wrapError('flush cache by pattern', undefined, async () => {
+      const keys = await this.client.keys(pattern);
+
+      if (keys.length === 0) {
+        return 0;
+      }
+
+      return this.client.del(...keys);
+    });
+  }
+
   async close(): Promise<boolean> {
     return this.wrapError('close connection', undefined, async () => {
       const result = await this.client.quit();
diff --git a/src/services/github.service.ts b/src/services/github.service.ts
index e25cfcd..3dda4a0 100644
--- a/src/services/github.service.ts
+++ b/src/services/github.service.ts
@@ -138,7 +138,7 @@ export class GitHubService {
         pull_number
       });
 
-      const filePromises = files.data.map(async (file) => {
+      const filePromises = files.data.map(async (file: RestEndpointMethodTypes['pulls']['listFiles']['response']['data'][number]) => {
         const content = await context.octokit.repos.getContent({
           owner,
           repo,
diff --git a/src/services/queue.service.ts b/src/services/queue.service.ts
index 66b060c..4c75bb0 100644
--- a/src/services/queue.service.ts
+++ b/src/services/queue.service.ts
@@ -1,21 +1,21 @@
-import pQueue, { Options, QueueAddOptions } from 'p-queue';
-import PriorityQueue from 'p-queue/dist/priority-queue';
+import pQueue from 'p-queue';
 import pRetry, { Options as pRetryOption } from 'p-retry';
 
 type TaskFunction<T> = () => Promise<T>;
+type PQueueOptions = ConstructorParameters<typeof pQueue>[0];
 
 export class QueueService {
   private static instance: QueueService;
   private queue: pQueue;
   private defaultRetryOptions: pRetryOption;
 
-  private constructor(queueOptions: Options<PriorityQueue, QueueAddOptions>, retryOptions: pRetryOption) {
+  private constructor(queueOptions: PQueueOptions, retryOptions: pRetryOption) {
     this.queue = new pQueue(queueOptions);
     this.defaultRetryOptions = retryOptions;
   }
 
   public static getInstance(
-    queueOptions: Options<PriorityQueue, QueueAddOptions> = { concurrency: 5, interval: 3000 },
+    queueOptions: PQueueOptions = { concurrency: 5, interval: 3000 },
     retryOptions: pRetryOption = { minTimeout: 1000, maxTimeout: 5000, retries: 3, factor: 2 }
   ): QueueService {
     if (!QueueService.instance) {
diff --git a/src/utils/chat-config.util.ts b/src/utils/chat-config.util.ts
index 7b44649..415a7d7 100644
--- a/src/utils/chat-config.util.ts
+++ b/src/utils/chat-config.util.ts
@@ -56,7 +56,7 @@ export class ChatConfig {
     } else if (isInlineComment(context.payload) || isPullRequestComment(context.payload)) {
       return config.chat['stop-on']['pull-requests'].closed;
     } else if (isIssue(context.payload) || isIssueComment(context.payload)) {
-      return config.chat['stop-on'].issues.locked;
+      return config.chat['stop-on'].issues.closed;
     } else {
       throw new SystemError('Unhandled case');
     }
diff --git a/src/utils/github.util.ts b/src/utils/github.util.ts
index 60c8f6d..441a032 100644
--- a/src/utils/github.util.ts
+++ b/src/utils/github.util.ts
@@ -1,37 +1,42 @@
 import { DiffLine } from '~common/types';
 
-const hunkRegex = /@@ -\d+(?:,\d+)? \+(\d+)(?:,(\d+))? @@([\s\S]*?)(?=@@|$)/g;
-
 export const extractDiffsFromPatch = (patch: string): DiffLine[] => {
-  const diffLines = [];
+  const diffLines: DiffLine[] = [];
+  const hunkRegex = /@@ -\d+(?:,\d+)? \+(\d+)(?:,\d+)? @@([\s\S]*?)(?=@@|$)/g;
 
   let match;
   while ((match = hunkRegex.exec(patch)) !== null) {
-    const allCleanedLines = match[3].split('\n').flatMap((line) => (!!line.trim() ? line.trim() : []));
-    const firstAdditionIndex = allCleanedLines.findIndex((line) => line.startsWith('+'));
-    const totalLinesBeforeFirstAddition = allCleanedLines.filter(
-      (line, lineIndex) => /^[^-+]/.test(line) && lineIndex < firstAdditionIndex
-    ).length;
-    const firstDeletionIndex = allCleanedLines.findIndex((line) => line.startsWith('-'));
-    const totalLinesAfterLastAddition = allCleanedLines.filter(
-      (line, lineIndex) => /^[^-+]/.test(line) && lineIndex < firstDeletionIndex
-    ).length;
-
-    const start = parseInt(match[1], 10) + totalLinesBeforeFirstAddition;
-    const lineCount = match[2] ? parseInt(match[2], 10) : 1;
-    const end = start - totalLinesBeforeFirstAddition + lineCount - 1 - totalLinesAfterLastAddition;
-
-    const addition = allCleanedLines
-      .filter((line) => line.startsWith('+'))
-      .map((line) => line.slice(1))
-      .join('\n');
-
-    const deletion = allCleanedLines
-      .filter((line) => line.startsWith('-'))
-      .map((line) => line.slice(1))
-      .join('\n');
-
-    diffLines.push({ start, end, addition, deletion });
+    let lineNum = parseInt(match[1], 10);
+    let startLine: number | null = null;
+    let endLine: number | null = null;
+    const addedLines: string[] = [];
+    const deletedLines: string[] = [];
+
+    const lines = match[2].split('\n');
+
+    for (const line of lines) {
+      if (line.startsWith('+')) {
+        if (startLine === null) startLine = lineNum;
+        endLine = lineNum;
+        addedLines.push(line.slice(1));
+        lineNum++;
+      } else if (line.startsWith('-')) {
+        deletedLines.push(line.slice(1));
+        // Deleted lines do not advance the new-file line counter
+      } else if (line.trim() !== '') {
+        // Context line — counts in both old and new file
+        lineNum++;
+      }
+    }
+
+    if (startLine !== null && endLine !== null) {
+      diffLines.push({
+        start: startLine,
+        end: endLine,
+        addition: addedLines.join('\n'),
+        deletion: deletedLines.join('\n')
+      });
+    }
   }
 
   return diffLines;
diff --git a/tests/utils/chat-config.util.test.ts b/tests/utils/chat-config.util.test.ts
index 60268ff..f392586 100644
--- a/tests/utils/chat-config.util.test.ts
+++ b/tests/utils/chat-config.util.test.ts
@@ -259,7 +259,7 @@ describe('ChatConfig', () => {
         },
         'stop-on': {
           discussions: { locked: true, closed: false },
-          issues: { locked: false, draft: true },
+          issues: { locked: false, draft: true, closed: true },
           'pull-requests': { locked: false, draft: false, merged: true, closed: false }
         },
         allow: {
@@ -290,7 +290,7 @@ describe('ChatConfig', () => {
 
     expect(ChatConfig.getChatStopOnClosed(contextDiscussion, config)).toBe(false);
     expect(ChatConfig.getChatStopOnClosed(contextInlineComment, config)).toBe(false);
-    expect(ChatConfig.getChatStopOnClosed(contextIssue, config)).toBe(false);
+    expect(ChatConfig.getChatStopOnClosed(contextIssue, config)).toBe(true); // fixed: reads .closed not .locked
 
     expect(ChatConfig.getChatAllow(contextDiscussion, config)).toBe(true);
     expect(ChatConfig.getChatAllow(contextInlineComment, config)).toBe(true);
diff --git a/tsconfig.json b/tsconfig.json
index 724cc80..e818416 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,8 +1,9 @@
 {
+  "ignoreDeprecations": true,
   "compilerOptions": {
     "target": "ES2022",
     "module": "ES2022",
-    "moduleResolution": "Node",
+    "moduleResolution": "Bundler",
     "incremental": true,
     "strict": true,
     "sourceMap": true,
@@ -26,10 +27,15 @@
     "declaration": false,
     "outDir": "dist",
     "rootDir": "src",
-    "typeRoots": ["types", "./node_modules/@types"],
+    "typeRoots": [
+      "types",
+      "./node_modules/@types"
+    ],
     "baseUrl": "./",
     "paths": {
-      "~*": ["./src/*"]
+      "~*": [
+        "./src/*"
+      ]
     }
   },
   "exclude": [
@@ -40,5 +46,5 @@
   "include": [
     "src",
     "types"
-  ]
+  ],
 }