perf(web): trim terminal link delimiters in linear time

apps/web/src/terminal-links.test.ts

@@ -124,6 +124,20 @@ describe("extractTerminalLinks", () => {
     ]);
   });
 
+  it.each([
+    ["https://example.com/a(b)c)", "https://example.com/a(b)c"],
+    ["https://example.com/(docs)", "https://example.com/(docs)"],
+    ["https://example.com/docs)}])", "https://example.com/docs)"],
+    ["https://example.com/docs):", "https://example.com/docs):"],
+    ["/tmp/a[b]c]", "/tmp/a[b]c"],
+    ["/tmp/docs)}])", "/tmp/docs)"],
+    ["/tmp/docs):", "/tmp/docs"],
+  ])("trims only unbalanced closing delimiters from %s", (raw, text) => {
+    expect(extractTerminalLinks(`see ${raw}`)).toEqual([
+      { kind: isTerminalUrl(text) ? "url" : "path", text, start: 4, end: 4 + text.length },
+    ]);
+  });
+
   it.each([
     "src/żółć.ts:12:7",
     "żółć/main.ts:12",

apps/web/src/terminal-links.ts

@@ -39,7 +39,6 @@ const URL_PATTERN = /https?:\/\/[^\s"'`<>]+/giu;
 const POWERSHELL_PROMPT_PATH_PATTERN = /^PS ((?:[A-Za-z]:[\\/]|\\\\|\/)[^>\r\n]*)>/u;
 // Bare paths start only at a segment boundary: hover detection runs this on
 // every frame, so separator-free output must not be rescanned at every suffix.
-// For the same reason `]` needs its `[`: trimming a long run of `]` is quadratic.
 // Parenthesized path segments need a following slash to distinguish compiler locations.
 const FILE_PATH_PATTERN =
   /(?:~[\\/]|\.{1,2}[\\/]|\/|[A-Za-z]:[\\/]|\\\\)[^\s"'`<>]+|(?<![\p{L}\p{M}\p{N}._-])[\p{L}\p{M}\p{N}._-]+(?:[\\/](?:[\p{L}\p{M}\p{N}._$+@-]|\[{1,2}[\p{L}\p{M}\p{N}._-]+\]{1,2}|\([\p{L}\p{M}\p{N}._-]+\)(?=[\\/]))+)+(?:(?::\d+){1,2}|\(\d+,\d+\)(?=:\s+(?:error|warning) TS\d+:))?/gu;
@@ -59,25 +58,26 @@ const SCHEME_URL_PATTERN = /(?<![A-Za-z\d+.-])[+-]?[A-Za-z][A-Za-z\d+.-]+:\/\/[^
 const SCP_REMOTE_PATTERN = /(?<![\w.@-])[\w.-]+@[\w.-]+:[^\s"'`<>]+/gu;
 
 function trimClosingDelimiters(value: string, kind: TerminalLinkKind): string {
-  let output = value.replace(
+  const output = value.replace(
     kind === "path" ? TRAILING_PATH_PUNCTUATION_PATTERN : TRAILING_PUNCTUATION_PATTERN,
     "",
   );
   if (output.length === 0) return output;
+  let end = output.length;
 
   const trimUnbalanced = (open: string, close: string) => {
-    while (output.endsWith(close)) {
-      const opens = output.split(open).length - 1;
-      const closes = output.split(close).length - 1;
-      if (opens >= closes) return;
-      output = output.slice(0, -1);
+    if (output[end - 1] !== close) return;
+    let excess = output.split(close).length - output.split(open).length;
+    while (excess > 0 && output[end - 1] === close) {
+      end -= 1;
+      excess -= 1;
     }
   };
 
   trimUnbalanced("(", ")");
   trimUnbalanced("[", "]");
   trimUnbalanced("{", "}");
-  return output;
+  return output.slice(0, end);
 }
 
 function overlaps(a: { start: number; end: number }, b: { start: number; end: number }): boolean {