fix: proper debouncing of fs events in '--watch'

.changeset/blue-plums-chew.md

@@ -0,0 +1,5 @@
+---
+"clarigen-deno": patch
+---
+
+Fixed an issue with `clarigen --watch`, where the "file watcher" would be triggered multiple times in a row, where it should have been debounced.

contracts/tester.clar

@@ -4,8 +4,6 @@
 
 (define-map demo-map { a: uint } bool)
 
-(define-non-fungible-token names { name: (buff 48), namespace: (buff 20) })
-
 (define-read-only (square (n uint)) (* n n))
 
 (define-read-only (get-tup) {
@@ -36,4 +34,6 @@
   (buffa (buff 10))
   )
   (ok true)
-)
+)
+
+(define-non-fungible-token names { name: (buff 48), namespace: (buff 20) })

src/cli/commands/default.ts

@@ -1,7 +1,7 @@
-import { getLevelByName } from '../../deps.ts';
+import { getLevelByName, Kia } from '../../deps.ts';
 import { Command } from '../cli-deps.ts';
 import { VERSION } from '../version.ts';
-import { log } from '../logger.ts';
+import { log, makeSpinner } from '../logger.ts';
 import { generate } from '../generate.ts';
 import { watch } from '../watch.ts';
 
@@ -12,6 +12,15 @@ type Options = ActionArgs[0];
 export async function defaultAction(opts: Options) {
   log.debug(`Starting default command with options: %j`, opts);
   if (opts.watch) {
+    let spinner: Kia | undefined;
+    if (log.level > getLevelByName('DEBUG')) {
+      spinner = makeSpinner('Generating types');
+      spinner.start();
+    }
+    await generate();
+    if (spinner?.isSpinning()) {
+      spinner.succeed('Watching for file changes');
+    }
     await watch();
   } else {
     await generate();

src/cli/logger.ts

@@ -1,4 +1,12 @@
-import { colors, ConsoleHandler, logger, LogRecord, sprintf } from '../deps.ts';
+import {
+  colors,
+  ConsoleHandler,
+  Kia,
+  logger,
+  LogRecord,
+  Spinners,
+  sprintf,
+} from '../deps.ts';
 
 const LEVEL_PREFIX: { [key: number]: string } = {
   [logger.LogLevels.INFO]: colors.blue('info'),
@@ -32,3 +40,11 @@ await logger.setup({
 });
 
 export const log = logger.getLogger();
+
+export function makeSpinner(text: string) {
+  return new Kia({
+    spinner: Spinners.arc,
+    text,
+    prefixText: colors.magenta(`[Clarigen] `),
+  });
+}

src/cli/watch.ts

@@ -6,11 +6,18 @@ import { cwdRelative } from './cli-utils.ts';
 
 const runDelay = 3000;
 let lastRun = new Date().getTime();
+let isRunning = false;
 
 export function shouldRun(_event: Deno.FsEvent) {
-  const isDelayed = new Date().getTime() - lastRun > runDelay;
+  const isDelayed = (new Date().getTime() - lastRun) > runDelay;
+  let filesOk = false;
+  _event.paths.forEach((f) => {
+    if (f.endsWith('.clar') || f.endsWith('.toml')) {
+      filesOk = true;
+    }
+  });
   lastRun = new Date().getTime();
-  return isDelayed;
+  return isDelayed && filesOk && !isRunning;
 }
 
 export function logFsEvent(event: Deno.FsEvent) {
@@ -33,11 +40,23 @@ export async function watch() {
   const watcher = Deno.watchFs(paths);
   for await (const event of watcher) {
     if (shouldRun(event)) {
+      isRunning = true;
       logFsEvent(event);
       const start = new Date().getTime();
-      await generate();
-      const diff = new Date().getTime() - start;
-      log.debug(colors.black('Done in %.3fs'), diff / 1000);
+      setTimeout(async () => {
+        try {
+          await generate();
+        } catch (error) {
+          if ('message' in error) {
+            log.error(error.message);
+          } else {
+            log.error(error);
+          }
+        }
+        const diff = new Date().getTime() - start;
+        log.debug(colors.black('Done in %.3fs'), diff / 1000);
+        isRunning = false;
+      }, 1);
     }
   }
 }

src/deps.ts

@@ -39,3 +39,5 @@ export {
   unknown,
 } from 'https://denoporter.sirjosh.workers.dev/v1/deno.land/x/computed_types/src/index.ts';
 export type { Type } from 'https://denoporter.sirjosh.workers.dev/v1/deno.land/x/computed_types/src/index.ts';
+export { default as Kia } from 'https://deno.land/x/kia@0.4.1b/mod.ts';
+export { Spinners } from 'https://deno.land/x/kia@0.4.1b/spinners.ts';