Refactor RegExp pattern matcher

Author: Chuanqi Sun

src/lib/utils/markdown.ts

@@ -0,0 +1,6 @@
+import { escapeRegExp } from "./regexp";
+
+export function getEntryPatternByHref(href: string): RegExp {
+  const existingItemPattern = String.raw`^- \[.+\]\(${escapeRegExp(href)}\).*$`;
+  return new RegExp(existingItemPattern, "m");
+}

src/lib/utils/merge-content.ts

@@ -1,7 +1,6 @@
-import { escapeRegExp } from "./regexp";
+import { getEntryPatternByHref } from "./markdown";
 
 export function mergeContent(newEntryHref: string, newEntry: string, existinContent: string): string {
-  const existingItemPattern = String.raw`^- \[.+\]\(${escapeRegExp(newEntryHref)}\).*$`;
-  const replaceResult = existinContent.replace(new RegExp(existingItemPattern, "m"), newEntry);
+  const replaceResult = existinContent.replace(getEntryPatternByHref(newEntryHref), newEntry);
   return replaceResult === existinContent ? `${newEntry}\n${existinContent}` : replaceResult;
 }

src/lib/utils/regexp.ts

@@ -1,4 +1,4 @@
 // ref: https://stackoverflow.com/questions/3446170/escape-string-for-use-in-javascript-regex
-export function escapeRegExp(string) {
-  return string.replace(/[.*+?^${}()|[\]\\]/g, "\\$&"); // $& means the whole matched string
+export function escapeRegExp(input: string) {
+  return input.replace(/[.*+?^${}()|[\]\\]/g, "\\$&"); // $& means the whole matched string
 }

src/popup/view.ts

@@ -1,5 +1,5 @@
 import { fitTextareaToContent } from "../lib/utils/fit-textarea-to-content";
-import { escapeRegExp } from "../lib/utils/regexp";
+import { getEntryPatternByHref } from "../lib/utils/markdown";
 import type { FullModel } from "./model";
 
 const $ = document.querySelector.bind(document);
@@ -101,8 +101,7 @@ export class View {
     }
 
     if (href !== previousState.href || markdownString !== previousState.markdownString) {
-      const existingItemPattern = String.raw`^- \[.+\]\(${escapeRegExp(href)}\).*$`;
-      const isExistingUrl = markdownString?.match(new RegExp(existingItemPattern, "m"));
+      const isExistingUrl = markdownString?.match(getEntryPatternByHref(href!));
       existingLinkMarker.hidden = !isExistingUrl;
     }