refactor: simplify PestV2Fixer and remove PestV3Fixer indirection

- Remove PestV3Fixer object: truncatedId() was only used internally by
  AliasMap.set() in the same file; replace with a module-level private function
- Remove PestV3Fixer re-export from PestFixer barrel (no external consumer)
- Simplify decodeDescribePart: replace 17-line while-loop tokenizer with
  placeholder approach (__ → \0, split _, restore \0)
- Merge double ternary on datasetIdx into a single destructure

Author: recca0120

packages/phpunit/src/TestIdentifier/PestFixer.ts

@@ -3,7 +3,7 @@ import type { TestResultCache } from '../TestOutput/TestResultCache';
 
 export { PestV1Fixer } from './PestV1Fixer';
 export { PestV2Fixer } from './PestV2Fixer';
-export { AliasMap, PestV3Fixer } from './PestV3Fixer';
+export { AliasMap } from './PestV3Fixer';
 
 export const PestFixer = {
     fixNoTestStarted(cache: TestResultCache, testResult: TestFailed | TestIgnored) {

packages/phpunit/src/TestIdentifier/PestV2Fixer.ts

@@ -5,23 +5,10 @@ function hasPrefix(id?: string) {
 }
 
 function decodeDescribePart(inner: string): string {
-    const segments: string[] = [];
-    let current = '';
-    let i = 0;
-    while (i < inner.length) {
-        if (inner[i] === '_' && inner[i + 1] === '_') {
-            current += '_';
-            i += 2;
-        } else if (inner[i] === '_') {
-            segments.push(current);
-            current = '';
-            i++;
-        } else {
-            current += inner[i];
-            i++;
-        }
-    }
-    segments.push(current);
+    const segments = inner
+        .replace(/__/g, '\0')
+        .split('_')
+        .map((s) => s.replace(/\0/g, '_'));
     const isFQN = segments.every((p) => /^[A-Z]/.test(p));
     return `\`${segments.join(isFQN ? '\\' : ' ')}\``;
 }
@@ -36,8 +23,10 @@ function decodeEvaluable(encoded: string): string {
     const methodFull = encoded.slice(prefixIdx + PREFIX.length);
 
     const datasetIdx = methodFull.search(/\s+with\s+data\s+set\s+/);
-    const methodPart = datasetIdx >= 0 ? methodFull.slice(0, datasetIdx) : methodFull;
-    const datasetSuffix = datasetIdx >= 0 ? methodFull.slice(datasetIdx) : '';
+    const [methodPart, datasetSuffix] =
+        datasetIdx >= 0
+            ? [methodFull.slice(0, datasetIdx), methodFull.slice(datasetIdx)]
+            : [methodFull, ''];
 
     const segments = methodPart.split('_\u2192_');
     if (segments.length < 2) {

packages/phpunit/src/TestIdentifier/PestV3Fixer.ts

@@ -1,21 +1,19 @@
 // Pest v3 bug: Str::beforeLast uses mb_strrpos (char offset) with substr (byte offset).
 // The → character (U+2192) is 3 UTF-8 bytes but 1 char, so names are truncated
 // by 2 bytes per → character.
-export const PestV3Fixer = {
-    truncatedId(id: string): string | undefined {
-        const count = (id.match(/\u2192/g) ?? []).length;
-        if (count === 0) {
-            return undefined;
-        }
+function truncatedId(id: string): string | undefined {
+    const count = (id.match(/\u2192/g) ?? []).length;
+    if (count === 0) {
+        return undefined;
+    }
 
-        return id.slice(0, -count * 2);
-    },
-};
+    return id.slice(0, -count * 2);
+}
 
 export class AliasMap<T> extends Map<string, T> {
     override set(id: string, item: T): this {
         super.set(id, item);
-        const truncated = PestV3Fixer.truncatedId(id);
+        const truncated = truncatedId(id);
         if (truncated) {
             super.set(truncated, item);
         }