From 25b9230f4d90ec5a742c36d905add8bd89dc6d4d Mon Sep 17 00:00:00 2001
From: Nicolas DUBIEN <github@dubien.org>
Date: Sun, 16 Aug 2026 17:05:35 +0200
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20Add=20ability=20to=20configure=20pl?=
 =?UTF-8?q?ugins=20globally=20(#7222)?=
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## Description

<!-- Describe your change and explain what this PR is trying to solve
-->

To date it was only possible to configure plugins in a local fashion. As
such one was not capable of defining a plugin for all its properties at
once.

The newly added API called `installGlobalPlugin` should unlock that
capability.

<!-- Add any additional context here -->

## Checklist

— _Don't delete this checklist and make sure you do the following before
opening the PR_

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code was hand-written, AI-generated, copied from external sources or
produced by any other tool
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by running `pnpm run bump` or by following the instructions from the
changeset bot
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unrelated changes
- [ ] I followed the [gitmoji](https://gitmoji.dev/) specification for
the name of the PR, including the package scope (e.g. `🐛(vitest)
Something...`) when the change targets a package other than `fast-check`
- [ ] I added relevant tests and they would have failed without my PR
(when applicable)

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---
 .changeset/vast-mangos-end.md                 |  5 +++
 .../fast-check/src/check/runner/Runner.ts     | 39 +++++++++++++------
 .../runner/configuration/GlobalPlugins.ts     | 28 +++++++++++++
 packages/fast-check/src/fast-check-default.ts |  2 +
 website/docs/advanced/plugins.md              | 10 +++++
 website/docs/configuration/global-settings.md |  4 ++
 6 files changed, 76 insertions(+), 12 deletions(-)
 create mode 100644 .changeset/vast-mangos-end.md
 create mode 100644 packages/fast-check/src/check/runner/configuration/GlobalPlugins.ts

diff --git a/.changeset/vast-mangos-end.md b/.changeset/vast-mangos-end.md
new file mode 100644
index 00000000..e1ca8898
--- /dev/null
+++ b/.changeset/vast-mangos-end.md
@@ -0,0 +1,5 @@
+---
+"fast-check": minor
+---
+
+✨ Add ability to configure plugins globally
diff --git a/packages/fast-check/src/check/runner/Runner.ts b/packages/fast-check/src/check/runner/Runner.ts
index e8115e02..b704fbf1 100644
--- a/packages/fast-check/src/check/runner/Runner.ts
+++ b/packages/fast-check/src/check/runner/Runner.ts
@@ -18,6 +18,7 @@ import type { IAsyncProperty } from '../property/AsyncProperty.js';
 import type { IProperty } from '../property/Property.js';
 import type { Value } from '../arbitrary/definition/Value.js';
 import type { Plugin, PluginInstance } from '../plugin/Plugin.js';
+import { readInstalledGlobalPlugins } from './configuration/GlobalPlugins.js';
 
 /** @internal */
 function runIt<Ts>(
@@ -65,6 +66,26 @@ async function asyncPropertyExecution<Ts>(property: IRawProperty<Ts>, v: Ts) {
   return out;
 }
 
+function applyPlugins<Ts>(
+  plugins: Plugin<Ts>[],
+  pluginOffset: number,
+  crossPluginContext: { [K in any]?: unknown },
+  run: IRawProperty<Ts>['run'],
+  pluginAfterAllCallbacks: Required<PluginInstance<Ts>>['afterAll'][],
+) {
+  let nextRun = run;
+  for (let index = 0; index !== plugins.length; ++index) {
+    const pluginInstance = plugins[index](pluginOffset, crossPluginContext);
+    if (pluginInstance.decorateRun !== undefined) {
+      nextRun = pluginInstance.decorateRun(nextRun);
+    }
+    if (pluginInstance.afterAll !== undefined) {
+      pluginAfterAllCallbacks.push(pluginInstance.afterAll.bind(pluginInstance));
+    }
+  }
+  return nextRun;
+}
+
 /**
  * Run the property, do not throw contrary to {@link assert}
  *
@@ -125,21 +146,15 @@ function check<Ts>(rawProperty: IRawProperty<Ts>, params?: Parameters<Ts>): unkn
     throw new Error('Invalid parameters encountered, only asyncProperty can be used when asyncReporter specified');
   const property = decorateProperty(rawProperty, qParams);
 
-  const pluginSharedSessionContext: { [K in any]?: unknown } = {};
-  const plugins: Plugin<Ts>[] = qParams.plugins;
-  const pluginAfterAllCallbacks: Required<PluginInstance<Ts>>['afterAll'][] = [];
   let run: typeof property.run = property.isAsync()
     ? async (v) => asyncPropertyExecution(property, v)
     : (v) => propertyExecution(property, v);
-  for (let index = 0; index !== plugins.length; ++index) {
-    const pluginInstance = plugins[index](index, pluginSharedSessionContext);
-    if (pluginInstance.decorateRun !== undefined) {
-      run = pluginInstance.decorateRun(run);
-    }
-    if (pluginInstance.afterAll !== undefined) {
-      pluginAfterAllCallbacks.push(pluginInstance.afterAll.bind(pluginInstance));
-    }
-  }
+  const pluginAfterAllCallbacks: Required<PluginInstance<Ts>>['afterAll'][] = [];
+
+  const crossPluginContext: { [K in any]?: unknown } = {};
+  const globalPlugins = readInstalledGlobalPlugins();
+  run = applyPlugins(globalPlugins, 0, crossPluginContext, run, pluginAfterAllCallbacks);
+  run = applyPlugins(qParams.plugins, globalPlugins.length, crossPluginContext, run, pluginAfterAllCallbacks);
 
   const maxInitialIterations = qParams.path.length === 0 || qParams.path.indexOf(':') === -1 ? qParams.numRuns : -1;
   const maxSkips = qParams.numRuns * qParams.maxSkipsPerRun;
diff --git a/packages/fast-check/src/check/runner/configuration/GlobalPlugins.ts b/packages/fast-check/src/check/runner/configuration/GlobalPlugins.ts
new file mode 100644
index 00000000..c488f899
--- /dev/null
+++ b/packages/fast-check/src/check/runner/configuration/GlobalPlugins.ts
@@ -0,0 +1,28 @@
+import type { Plugin } from '../../plugin/Plugin.js';
+
+const globalPlugins: Plugin<any>[] = [];
+
+/**
+ * Install a plugin to be used by all the runners
+ * Installed plugins come before the ones passed via the `plugins` option of the run.
+ *
+ * @example
+ * ```typescript
+ * fc.installGlobalPlugin(myPlugin());
+ * //...
+ * fc.assert(myProp, { plugins: [myOtherPlugin()] })
+ * // equivalent to { plugins: [myPlugin(), myOtherPlugin()] }
+ * ```
+ *
+ * @param plugin - Plugin to be installed globally
+ *
+ * @remarks Since 4.10.0
+ * @public
+ */
+export function installGlobalPlugin(plugin: Plugin<unknown>): void {
+  globalPlugins.push(plugin);
+}
+
+export function readInstalledGlobalPlugins(): Plugin<any>[] {
+  return globalPlugins;
+}
diff --git a/packages/fast-check/src/fast-check-default.ts b/packages/fast-check/src/fast-check-default.ts
index 93a77d74..0cda5d19 100644
--- a/packages/fast-check/src/fast-check-default.ts
+++ b/packages/fast-check/src/fast-check-default.ts
@@ -209,6 +209,7 @@ import { noBias } from './arbitrary/noBias.js';
 import { limitShrink } from './arbitrary/limitShrink.js';
 import type { RandomGenerator } from './random/generator/RandomGenerator.js';
 import type { Plugin, PluginInstance } from './check/plugin/Plugin.js';
+import { installGlobalPlugin } from './check/runner/configuration/GlobalPlugins.js';
 
 // Explicit cast into string to avoid to have __type: "process.env.__PACKAGE_TYPE__"
 /**
@@ -452,6 +453,7 @@ export {
   configureGlobal,
   readConfigureGlobal,
   resetConfigureGlobal,
+  installGlobalPlugin,
   ExecutionStatus,
   Random,
   Stream,
diff --git a/website/docs/advanced/plugins.md b/website/docs/advanced/plugins.md
index 076d1728..6b90ab7b 100644
--- a/website/docs/advanced/plugins.md
+++ b/website/docs/advanced/plugins.md
@@ -25,3 +25,13 @@ await fc.assert(fc.asyncProperty(...arbs, predicate), {
   plugins: [pluginA(...paramsForPluginA), pluginB(...paramsForPluginB)],
 });
 ```
+
+## Installing plugins globally
+
+Plugins needed by all your properties can be installed once, typically in a [setup file](/docs/configuration/global-settings/#integration-with-test-frameworks), with `installGlobalPlugin`.
+
+```ts
+fc.installGlobalPlugin(pluginA());
+```
+
+Installed plugins run before the ones passed to the runner, so the snippet above followed by `fc.assert(myProp, { plugins: [pluginB()] })` is equivalent to `plugins: [pluginA(), pluginB()]`.
diff --git a/website/docs/configuration/global-settings.md b/website/docs/configuration/global-settings.md
index c375a900..063c3e5b 100644
--- a/website/docs/configuration/global-settings.md
+++ b/website/docs/configuration/global-settings.md
@@ -58,6 +58,10 @@ fc.configureGlobal({ ...fc.readConfigureGlobal(), ...myNewOptions });
 You can also fully reset all the global options by calling `resetConfigureGlobal`.
 :::
 
+:::info Plugins
+[Plugins](/docs/advanced/plugins/) cannot be shared via `configureGlobal`, they have their own installer: `fc.installGlobalPlugin(myPlugin())`.
+:::
+
 Resources: [API reference](/docs/api/functions/configureGlobal).  
 Available since 1.18.0.
 
-- 
2.51.2