DiffMatchPatch for faster diffing (#158)

* DiffMatchPatch for faster diffing

package.json

@@ -22,6 +22,7 @@
  "@rollup/plugin-node-resolve": "^11.2.1",
  "@rollup/plugin-typescript": "^8.2.1",
  "@types/diff": "^5.0.1",
+ "@types/diff-match-patch": "^1.0.32",
  "@types/jest": "^26.0.24",
  "@types/node": "^14.17.9",
  "@typescript-eslint/eslint-plugin": "^4.30.0",
@@ -39,7 +40,7 @@
  },
  "dependencies": {
  "@types/js-yaml": "^4.0.3",
- "diff": "^4.0.2",
+ "diff-match-patch": "^1.0.5",
  "js-yaml": "^3.14.1",
  "moment": "^2.29.1",
  "remark": "^14.0.1",

src/main.ts

@@ -1,6 +1,6 @@
 import {App, Editor, EventRef, MarkdownView, Menu, Modal, Notice, Plugin, PluginSettingTab, Setting, TAbstractFile, TFile} from 'obsidian';
 import {LinterSettings, Options, rules, getDisabledRules} from './rules';
-import Diff from 'diff';
+import DiffMatchPatch from 'diff-match-patch';
 import moment from 'moment';
 import {BooleanOption, DropdownOption, MomentFormatOption, TextAreaOption, TextOption} from './option';
 import dedent from 'ts-dedent';
@@ -179,30 +179,33 @@ export default class LinterPlugin extends Plugin {
  const newText = this.lintText(oldText, file);
 
  // Replace changed lines
- const changes = Diff.diffChars(oldText, newText);
+ const dmp = new DiffMatchPatch.diff_match_patch(); // eslint-disable-line new-cap
+ const changes = dmp.diff_main(oldText, newText);
  let curText = '';
  changes.forEach((change) => {
  function endOfDocument(doc: string) {
  const lines = doc.split('\n');
  return {line: lines.length - 1, ch: lines[lines.length - 1].length};
  }
 
- if (change.added) {
- editor.replaceRange(change.value, endOfDocument(curText));
- curText += change.value;
- } else if (change.removed) {
+ const [type, value] = change;
+
+ if (type == DiffMatchPatch.DIFF_INSERT) {
+ editor.replaceRange(value, endOfDocument(curText));
+ curText += value;
+ } else if (type == DiffMatchPatch.DIFF_DELETE) {
  const start = endOfDocument(curText);
  let tempText = curText;
- tempText += change.value;
+ tempText += value;
  const end = endOfDocument(tempText);
  editor.replaceRange('', start, end);
  } else {
- curText += change.value;
+ curText += value;
  }
  });
 
- const charsAdded = changes.map((change) => change.added ? change.value.length : 0).reduce((a, b) => a + b, 0);
- const charsRemoved = changes.map((change) => change.removed ? change.value.length : 0).reduce((a, b) => a + b, 0);
+ const charsAdded = changes.map((change) => change[0] == DiffMatchPatch.DIFF_INSERT ? change[1].length : 0).reduce((a, b) => a + b, 0);
+ const charsRemoved = changes.map((change) => change[0] == DiffMatchPatch.DIFF_DELETE ? change[1].length : 0).reduce((a, b) => a + b, 0);
  this.displayChangedMessage(charsAdded, charsRemoved);
  }