Add -t/--filter flag for file path filtering

CLAUDE.md

@@ -12,6 +12,7 @@ Transcript-based shell integration test runner. Bun + TypeScript.
   - `--clean-env` — start with empty environment
   - `--path <path>` — prepend to `$PATH` (repeatable)
   - `--timeout <dur>` — per-command timeout (default `10s`)
+  - `-t, --filter <pattern>` — only run files whose path contains `<pattern>`
   - `-v, --verbose` — print each command as it runs
   - `--port-from <n>` — auto-assign `$PORT` starting from n (default `5400`)
   - `--parallel` — run files in parallel

README.md

@@ -113,6 +113,7 @@ Options:
   --clean-env      Start with empty environment
   --path <path>    Prepend <path> to PATH (repeatable)
   --timeout <dur>  Per-command timeout (default: "10s")
+  -t, --filter     Only run files matching <pattern> (substring match)
   -v, --verbose    Print each command as it runs
   --port-from <n>  Auto-assign $PORT starting from n (default: "5400")
   --parallel       Run files in parallel

src/cli/index.ts

@@ -80,20 +80,26 @@ program
   .option("--timeout <dur>", "Per-command timeout", "10s")
   .option("-v, --verbose", "Print each command as it runs")
   .option("--port-from <n>", "Auto-assign $PORT starting from <n>", "5400")
+  .option("-t, --filter <pattern>", "Only run files matching <pattern> (substring match)")
   .option("--parallel", "Run files in parallel")
   .action(async (fileArgs: string[], opts) => {
     const timeoutMs = parseDuration(opts.timeout)
     const paths = fileArgs.length > 0 ? fileArgs : ["."]
-    const files = await findShoutFiles(paths)
+    let files = await findShoutFiles(paths)
-
-    if (files.length === 0) {
-      console.error("No .shout files found")
-      process.exit(1)
-    }
 
     const start = performance.now()
     const results: TestResult[] = []
     const cwd = process.cwd()
+
+    if (opts.filter) {
+      const pattern = opts.filter
+      files = files.filter(f => relative(cwd, f).includes(pattern))
+    }
+
+    if (files.length === 0) {
+      console.error(opts.filter ? `No .shout files matching "${opts.filter}"` : "No .shout files found")
+      process.exit(1)
+    }
     const portFrom = parseInt(opts.portFrom, 10)
     if (Number.isNaN(portFrom)) {
       console.error("--port-from must be an integer")

web/index.html

@@ -248,6 +248,7 @@ Options:
   --clean-env      Start with empty environment
   --path <path>    Prepend <path> to PATH (repeatable)
   --timeout <dur>  Per-command timeout (default: "10s")
+  -t, --filter     Only run files matching <pattern> (substring match)
   -v, --verbose    Print each command as it runs
   --port-from <n>  Auto-assign $PORT starting from n (default: "5400")
   --parallel       Run files in parallel