Address PR #113 round 5: remove invalid 'e' flag, clarify parser comments

src/regex.ts — extractRegexToken():
- Remove 'e' from the allowed flag set: [gimsuydev]* -> [gimsuydv]*
  'e' is not a valid JavaScript RegExp flag; its presence would cause
  /pattern/e to be tokenised as a regex and then fail compilation,
  instead of being passed through unchanged as a plain query token.

src/regex.ts — splitTopLevelAlternation():
- Clarify truncated inline comments:
    depth: 'tracks unescaped ( nesting'
         → 'tracks unescaped \"(\" nesting depth outside character classes'
    inClass: 'tracks [...]'
           → 'tracks whether we are currently inside a character class [...]'

src/regex.test.ts:
- isRegexQuery('/pattern/e') → false (regression test)
- buildApiQuery('/pattern/e') → passthrough, regexFilter null

Author: shouze

src/regex.test.ts

@@ -33,6 +33,10 @@ describe("isRegexQuery", () => {
     // a suffix of non-flag characters must not be silently swallowed.
     expect(isRegexQuery("/useState/iSomething")).toBe(false);
   });
+
+  it("returns false for /pattern/e ('e' is not a valid JS RegExp flag)", () => {
+    expect(isRegexQuery("/pattern/e")).toBe(false);
+  });
 });
 
 // ─── buildApiQuery ────────────────────────────────────────────────────────────
@@ -51,6 +55,12 @@ describe("buildApiQuery — plain text passthrough", () => {
     expect(r.apiQuery).toBe("/useState/iSomething");
     expect(r.regexFilter).toBeNull();
   });
+
+  it("/pattern/e is NOT treated as a regex token ('e' is not a valid JS RegExp flag)", () => {
+    const r = buildApiQuery("/pattern/e");
+    expect(r.apiQuery).toBe("/pattern/e");
+    expect(r.regexFilter).toBeNull();
+  });
 });
 
 describe("buildApiQuery — longest literal extraction", () => {

src/regex.ts

@@ -90,10 +90,11 @@ function extractRegexToken(q: string): RegexToken | null {
   //   - the token ends at end-of-string or a whitespace boundary, so we don't
   //     accidentally match a prefix of a longer non-delimited word
   //     (e.g. /foo/iSomething must NOT be recognised as a regex token).
-  // The trailing flags cover all current JS RegExp flag letters:
+  // The trailing flags cover all valid JS RegExp flag letters:
   //   g (global), i (ignoreCase), m (multiline), s (dotAll),
   //   u (unicode), y (sticky), d (hasIndices ES2022), v (unicodeSets ES2023).
-  const m = q.match(/(?:^|\s)(\/(?:[^/\\\r\n]|\\.)+\/[gimsuydev]*)(?=$|\s)/);
+  // Note: 'e' is intentionally excluded — it is not a valid JS RegExp flag.
+  const m = q.match(/(?:^|\s)(\/(?:[^/\\\r\n]|\\.)+\/[gimsuydv]*)(?=$|\s)/);
   if (!m || !m[1]) return null;
   const raw = m[1].trim();
   const lastSlash = raw.lastIndexOf("/");
@@ -144,8 +145,8 @@ function extractApiTerm(pattern: string): { term: string; warn?: string } {
  */
 function splitTopLevelAlternation(pattern: string): string[] {
   const branches: string[] = [];
-  let depth = 0; // tracks unescaped ( nesting
-  let inClass = false; // tracks [...]
+  let depth = 0; // tracks unescaped '(' nesting depth outside character classes
+  let inClass = false; // tracks whether we are currently inside a character class [...]
   let current = "";
   let escaped = false; // true when current char is escaped by a preceding backslash