improve life cycle hooks typings (#8652)

* simpler hook types

* add changeset

* Update .changeset/plenty-bottles-prove.md

Co-authored-by: Saihajpreet Singh <saihajpreet.singh@gmail.com>

* only type changes

Co-authored-by: Saihajpreet Singh <saihajpreet.singh@gmail.com>

.changeset/plenty-bottles-prove.md

@@ -0,0 +1,6 @@
+---
+'@graphql-codegen/cli': patch
+'@graphql-codegen/plugin-helpers': major
+---
+
+improve typings for life cycle hooks

packages/graphql-codegen-cli/src/hooks.ts

@@ -4,7 +4,7 @@ import { exec } from 'child_process';
 import { delimiter, sep } from 'path';
 import { quote } from 'shell-quote';
 
-const DEFAULT_HOOKS: Types.LifecycleHooksDefinition<string[]> = {
+const DEFAULT_HOOKS: Types.LifecycleHooksDefinition = {
   afterStart: [],
   beforeDone: [],
   onWatchTriggered: [],
@@ -15,35 +15,38 @@ const DEFAULT_HOOKS: Types.LifecycleHooksDefinition<string[]> = {
   beforeAllFileWrite: [],
 };
 
-function normalizeHooks(
-  _hooks: Partial<Types.LifecycleHooksDefinition>
-): Types.LifecycleHooksDefinition<(string | Types.HookFunction)[]> {
+function normalizeHooks(_hooks: Partial<Types.LifecycleHooksDefinition>): {
+  [key in keyof Types.LifecycleHooksDefinition]: (string | Types.HookFunction)[];
+} {
   const keys = Object.keys({
     ...DEFAULT_HOOKS,
     ..._hooks,
   });
 
-  return keys.reduce((prev: Types.LifecycleHooksDefinition<(string | Types.HookFunction)[]>, hookName: string) => {
-    if (typeof _hooks[hookName] === 'string') {
-      return {
-        ...prev,
-        [hookName]: [_hooks[hookName]] as string[],
-      };
-    }
-    if (typeof _hooks[hookName] === 'function') {
-      return {
-        ...prev,
-        [hookName]: [_hooks[hookName]],
-      };
-    }
-    if (Array.isArray(_hooks[hookName])) {
-      return {
-        ...prev,
-        [hookName]: _hooks[hookName] as string[],
-      };
-    }
-    return prev;
-  }, {} as Types.LifecycleHooksDefinition<(string | Types.HookFunction)[]>);
+  return keys.reduce(
+    (prev: { [key in keyof Types.LifecycleHooksDefinition]: (string | Types.HookFunction)[] }, hookName: string) => {
+      if (typeof _hooks[hookName] === 'string') {
+        return {
+          ...prev,
+          [hookName]: [_hooks[hookName]] as string[],
+        };
+      }
+      if (typeof _hooks[hookName] === 'function') {
+        return {
+          ...prev,
+          [hookName]: [_hooks[hookName]],
+        };
+      }
+      if (Array.isArray(_hooks[hookName])) {
+        return {
+          ...prev,
+          [hookName]: _hooks[hookName] as string[],
+        };
+      }
+      return prev;
+    },
+    {} as { [key in keyof Types.LifecycleHooksDefinition]: (string | Types.HookFunction)[] }
+  );
 }
 
 function execShellCommand(cmd: string): Promise<string> {
@@ -72,10 +75,11 @@ function execShellCommand(cmd: string): Promise<string> {
 
 async function executeHooks(
   hookName: string,
-  scripts: (string | Types.HookFunction)[] = [],
+  _scripts: Types.LifeCycleHookValue = [],
   args: string[] = []
 ): Promise<void> {
   debugLog(`Running lifecycle hook "${hookName}" scripts...`);
+  const scripts = Array.isArray(_scripts) ? _scripts : [_scripts];
 
   const quotedArgs = quote(args);
   for (const script of scripts) {

packages/utils/plugins-helpers/src/types.ts

@@ -524,58 +524,60 @@ export namespace Types {
   export type PluginOutput = string | ComplexPluginOutput;
   export type HookFunction = (...args: any[]) => void | Promise<void>;
 
+  export type LifeCycleHookValue = string | HookFunction | (string | HookFunction)[];
+
   /**
    * @description All available lifecycle hooks
    * @additionalProperties false
    */
-  export type LifecycleHooksDefinition<T = string | HookFunction | (string | HookFunction)[]> = {
+  export type LifecycleHooksDefinition = {
     /**
      * @description Triggered with no arguments when the codegen starts (after the `codegen.yml` has beed parsed).
      *
      * Specify a shell command to run.
      */
-    afterStart: T;
+    afterStart: LifeCycleHookValue;
     /**
      * @description Triggered with no arguments, right before the codegen closes, or when watch mode is stopped.
      *
      * Specify a shell command to run.
      */
-    beforeDone: T;
+    beforeDone: LifeCycleHookValue;
     /**
      * @description Triggered every time a file changes when using watch mode.
      * Triggered with two arguments: the type of the event (for example, `changed`) and the path of the file.
      */
-    onWatchTriggered: T;
+    onWatchTriggered: LifeCycleHookValue;
     /**
      * @description Triggered in case of a general error in the codegen. The argument is a string containing the error.
      */
-    onError: T;
+    onError: LifeCycleHookValue;
     /**
      * @description Triggered after a file is written to the file-system. Executed with the path for the file.
      * If the content of the file hasn't changed since last execution - this hooks won't be triggered.
      *
      * > This is a very useful hook, you can use it for integration with Prettier or other linters.
      */
-    afterOneFileWrite: T;
+    afterOneFileWrite: LifeCycleHookValue;
     /**
      * @description Executed after writing all the files to the file-system.
      * Triggered with multiple arguments - paths for all files.
      */
-    afterAllFileWrite: T;
+    afterAllFileWrite: LifeCycleHookValue;
     /**
      * @description Triggered before a file is written to the file-system. Executed with the path for the file.
      *
      * If the content of the file hasn't changed since last execution - this hooks won't be triggered.
      */
-    beforeOneFileWrite: T;
+    beforeOneFileWrite: LifeCycleHookValue;
     /**
      * @description Executed after the codegen has done creating the output and before writing the files to the file-system.
      *
      * Triggered with multiple arguments - paths for all relevant files.
      *
      * > Not all the files will be actually written to the file-system, because this is triggered before checking if the file has changed since last execution.
      */
-    beforeAllFileWrite: T;
+    beforeAllFileWrite: LifeCycleHookValue;
   };
 
   export type SkipDocumentsValidationOptions =