fix(watch): reject fractional --capture intervals

README.md

@@ -126,7 +126,7 @@ tmux attach -t my-agent
 | `watch` | `--cli=claude` | CLI whose patterns classify the output; if no pattern set exists for the name (and none in `--patterns-dir`), pluk warns once on stderr and emits only `raw_output` (exit 0). `pluk patterns --cli=<name>` reports `no pattern set for <name>` and lists the available names |
 | `watch` | `--filter=type1,type2` | Emit only the listed event types (also accepted by `subscribe`); unknown or empty entries exit 2 |
 | `watch` | `--include-raw` | Also emit `raw_output` events |
-| `watch` | `--capture[=ms]` | Instead of reading stdin, poll `tmux capture-pane` and classify each whole rendered frame; useful for TUIs whose pipe-pane stream has no line feeds. Interval in milliseconds, default `1000`. With `--include-raw`, `raw_output` `data.line` is a whole ANSI-stripped screen |
+| `watch` | `--capture[=ms]` | Instead of reading stdin, poll `tmux capture-pane` and classify each whole rendered frame; useful for TUIs whose pipe-pane stream has no line feeds. Interval in milliseconds (positive integer), default `1000`. With `--include-raw`, `raw_output` `data.line` is a whole ANSI-stripped screen |
 | `watch` | `--pane=<target>` | tmux pane to poll in `--capture` mode (defaults to the session name) |
 | `watch` | `--patterns-dir=<dir>` | Load pattern files from this directory |
 | `patterns` | `--patterns-dir=<dir>` | Show the patterns loaded from this directory (same lookup as `watch`) |

changelog.d/fixed-291.md

@@ -0,0 +1 @@
+- `pluk watch --capture=<ms>` now rejects fractional intervals such as `--capture=1.5`, accepting only positive integers as documented (#291).

src/cli.ts

@@ -178,7 +178,7 @@ function cmdWatch(args: string[]): void {
   }
   if (capture !== undefined && capture !== 'true') {
     captureIntervalMs = Number(capture);
-    if (!Number.isFinite(captureIntervalMs) || captureIntervalMs <= 0) {
+    if (!Number.isInteger(captureIntervalMs) || captureIntervalMs <= 0) {
       console.error(`${paintStderr(ANSI_RED, 'Error:')} --capture expects a positive integer number of milliseconds`);
       process.exit(2);
     }

test/cli-watch-guard.test.js

@@ -86,7 +86,7 @@ test('run-tests.mjs propagates the child suite exit status', () => {
 
 // --- watch: invalid --capture interval is rejected -------------------------------
 
-for (const bad of ['0', '-5', 'abc', '']) {
+for (const bad of ['0', '-5', 'abc', '', '1.5']) {
   test(`watch --capture=${bad} exits 2 with a usage error`, () => {
     const { code, stderr } = run(CLI, ['watch', 'x', `--capture=${bad}`]);
     assert.equal(code, 2);