feature: new diffMaxChanges in parser config

If `diffMaxChanges` is set in parser config, and its value is exceeded for a given file diff, then parsing for this file is stopped, and `isTooBig` is set to `true` in the `DiffFile`

Author: Pierrci

src/__tests__/diff-parser-tests.ts

@@ -1975,5 +1975,149 @@ describe('DiffParser', () => {
         ]
       `);
     });
+
+    it('should stop parsing file and mark it as `isTooBig` if `diffMaxChanges` is set and excedeed', () => {
+      const diff =
+        'diff --git a/src/core/init.js b/src/core/init.js\n' +
+        'index e49196a..50f310c 100644\n' +
+        '--- a/src/core/init.js\n' +
+        '+++ b/src/core/init.js\n' +
+        '@@ -101,7 +101,7 @@ var rootjQuery,\n' +
+        '     // HANDLE: $(function)\n' +
+        '     // Shortcut for document ready\n' +
+        '     } else if ( jQuery.isFunction( selector ) ) {\n' +
+        '-      return typeof rootjQuery.ready !== "undefined" ?\n' +
+        '+      return rootjQuery.ready !== undefined ?\n' +
+        '         rootjQuery.ready( selector ) :\n' +
+        '         // Execute immediately if ready is not present\n' +
+        '         selector( jQuery );\n' +
+        'diff --git a/src/event.js b/src/event.js\n' +
+        'index 7336f4d..6183f70 100644\n' +
+        '--- a/src/event.js\n' +
+        '+++ b/src/event.js\n' +
+        '@@ -1,6 +1,5 @@\n' +
+        ' define([\n' +
+        '   "./core",\n' +
+        '-  "./var/strundefined",\n' +
+        '   "./var/rnotwhite",\n' +
+        '   "./var/hasOwn",\n' +
+        '   "./var/slice",\n';
+      const result = parse(diff, { diffMaxChanges: 1 });
+      expect(result).toMatchInlineSnapshot(`
+        Array [
+          Object {
+            "addedLines": 1,
+            "blocks": Array [
+              Object {
+                "header": "@@ -101,7 +101,7 @@ var rootjQuery,",
+                "lines": Array [
+                  Object {
+                    "content": "     // HANDLE: $(function)",
+                    "newNumber": 101,
+                    "oldNumber": 101,
+                    "type": "context",
+                  },
+                  Object {
+                    "content": "     // Shortcut for document ready",
+                    "newNumber": 102,
+                    "oldNumber": 102,
+                    "type": "context",
+                  },
+                  Object {
+                    "content": "     } else if ( jQuery.isFunction( selector ) ) {",
+                    "newNumber": 103,
+                    "oldNumber": 103,
+                    "type": "context",
+                  },
+                  Object {
+                    "content": "-      return typeof rootjQuery.ready !== \\"undefined\\" ?",
+                    "newNumber": undefined,
+                    "oldNumber": 104,
+                    "type": "delete",
+                  },
+                  Object {
+                    "content": "+      return rootjQuery.ready !== undefined ?",
+                    "newNumber": 104,
+                    "oldNumber": undefined,
+                    "type": "insert",
+                  },
+                ],
+                "newStartLine": 101,
+                "oldStartLine": 101,
+                "oldStartLine2": null,
+              },
+            ],
+            "checksumAfter": "50f310c",
+            "checksumBefore": "e49196a",
+            "deletedLines": 1,
+            "isCombined": false,
+            "isGitDiff": true,
+            "isTooBig": true,
+            "language": "js",
+            "mode": "100644",
+            "newName": "src/core/init.js",
+            "oldName": "src/core/init.js",
+          },
+          Object {
+            "addedLines": 0,
+            "blocks": Array [
+              Object {
+                "header": "@@ -1,6 +1,5 @@",
+                "lines": Array [
+                  Object {
+                    "content": " define([",
+                    "newNumber": 1,
+                    "oldNumber": 1,
+                    "type": "context",
+                  },
+                  Object {
+                    "content": "   \\"./core\\",",
+                    "newNumber": 2,
+                    "oldNumber": 2,
+                    "type": "context",
+                  },
+                  Object {
+                    "content": "-  \\"./var/strundefined\\",",
+                    "newNumber": undefined,
+                    "oldNumber": 3,
+                    "type": "delete",
+                  },
+                  Object {
+                    "content": "   \\"./var/rnotwhite\\",",
+                    "newNumber": 3,
+                    "oldNumber": 4,
+                    "type": "context",
+                  },
+                  Object {
+                    "content": "   \\"./var/hasOwn\\",",
+                    "newNumber": 4,
+                    "oldNumber": 5,
+                    "type": "context",
+                  },
+                  Object {
+                    "content": "   \\"./var/slice\\",",
+                    "newNumber": 5,
+                    "oldNumber": 6,
+                    "type": "context",
+                  },
+                ],
+                "newStartLine": 1,
+                "oldStartLine": 1,
+                "oldStartLine2": null,
+              },
+            ],
+            "checksumAfter": "6183f70",
+            "checksumBefore": "7336f4d",
+            "deletedLines": 1,
+            "isCombined": false,
+            "isGitDiff": true,
+            "language": "js",
+            "mode": "100644",
+            "newName": "src/event.js",
+            "oldName": "src/event.js",
+          },
+        ]
+      `);
+    });
   });
 });

src/diff-parser.ts

@@ -4,6 +4,7 @@ import { escapeForRegExp } from './utils';
 export interface DiffParserConfig {
   srcPrefix?: string;
   dstPrefix?: string;
+  diffMaxChanges?: number;
 }
 
 function getExtension(filename: string, language: string): string {
@@ -225,6 +226,13 @@ export function parse(diffInput: string, config: DiffParserConfig = {}): DiffFil
       currentLine.newNumber = newLine++;
     }
     currentBlock.lines.push(currentLine);
+    if (
+      typeof config.diffMaxChanges === 'number' &&
+      currentFile.addedLines + currentFile.deletedLines > config.diffMaxChanges
+    ) {
+      currentFile.isTooBig = true;
+      currentFile.blocks = [];
+    }
   }
 
   /*
@@ -299,6 +307,11 @@ export function parse(diffInput: string, config: DiffParserConfig = {}): DiffFil
       startFile();
     }
 
+    // Ignore remaining diff for current file if marked as too big
+    if (currentFile?.isTooBig) {
+      return;
+    }
+
     /*
      * We need to make sure that we have the three lines of the header.
      * This avoids cases like the ones described in:

src/types.ts

@@ -62,6 +62,7 @@ export interface DiffFile extends DiffFileName {
   isCopy?: boolean;
   isRename?: boolean;
   isBinary?: boolean;
+  isTooBig?: boolean;
   unchangedPercentage?: number;
   changedPercentage?: number;
   checksumBefore?: string | string[];