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// Copyright (c) 2026 Cloudflare, Inc.
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// Licensed under the Apache 2.0 license found in the LICENSE file or at:
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//     https://opensource.org/licenses/Apache-2.0
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//
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// Tests the `hasSubscribers` getter behavior of `Channel` and `TracingChannel`
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// when the `diagnostics_channel_has_subscribers_getter` compat flag is enabled.
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// Legacy method behavior is covered by `diagnostics-channel-test`.
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import { ok, strictEqual } from 'node:assert';
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import { channel, tracingChannel } from 'node:diagnostics_channel';
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export const test_channel_hasSubscribers_is_a_getter = {
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  async test() {
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    const ch = channel('getter-test');
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    // It is a boolean, not a function (matches Node.js).
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    strictEqual(typeof ch.hasSubscribers, 'boolean');
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    strictEqual(ch.hasSubscribers, false);
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    const listener = () => {};
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    ch.subscribe(listener);
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    strictEqual(ch.hasSubscribers, true);
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    ch.unsubscribe(listener);
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    strictEqual(ch.hasSubscribers, false);
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    // Defined on the prototype as a read-only getter.
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    const desc = Object.getOwnPropertyDescriptor(
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      Object.getPrototypeOf(ch),
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      'hasSubscribers'
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    );
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    ok(desc);
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    strictEqual(typeof desc.get, 'function');
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    strictEqual(desc.set, undefined);
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    strictEqual(desc.value, undefined);
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  },
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};
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export const test_tracingChannel_hasSubscribers_is_a_getter = {
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  async test() {
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    const tc = tracingChannel('tracing-getter-test');
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    strictEqual(typeof tc.hasSubscribers, 'boolean');
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    strictEqual(tc.hasSubscribers, false);
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    const listener = () => {};
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    // Each sub-channel independently flips the aggregate getter.
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    for (const sub of ['start', 'end', 'asyncStart', 'asyncEnd', 'error']) {
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      tc[sub].subscribe(listener);
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      strictEqual(tc.hasSubscribers, true, `via ${sub}`);
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      tc[sub].unsubscribe(listener);
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      strictEqual(tc.hasSubscribers, false, `after unsubscribing ${sub}`);
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    }
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    // TracingChannel.hasSubscribers should also be a prototype getter.
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    const desc = Object.getOwnPropertyDescriptor(
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      Object.getPrototypeOf(tc),
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      'hasSubscribers'
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    );
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    ok(desc);
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    strictEqual(typeof desc.get, 'function');
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    strictEqual(desc.set, undefined);
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    strictEqual(desc.value, undefined);
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  },
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};