PackageJson: Add overrides (#1287)

Author: SBoudrias

source/package-json.d.ts

@@ -208,6 +208,13 @@ export namespace PackageJson {
 	*/
 	type Dependency = Partial<Record<string, string>>;
 
+	/**
+	Recursive map describing selective dependency version overrides supported by npm.
+	*/
+	type DependencyOverrides = {
+		[packageName: string]: string | undefined | DependencyOverrides;
+	};
+
 	/**
 	Specifies requirements for development environment components such as operating systems, runtimes, or package managers. Used to ensure consistent development environments across the team.
 	*/
@@ -510,6 +517,11 @@ export namespace PackageJson {
 		*/
 		bundleDependencies?: string[];
 
+		/**
+		Overrides is used to support selective version overrides using npm, which lets you define custom package versions or ranges inside your dependencies.
+		*/
+		overrides?: DependencyOverrides;
+
 		/**
 		Engines that this package runs on.
 		*/

test-d/package-json.ts

@@ -37,6 +37,11 @@ expectType<string[] | undefined>(packageJson.bundleDependencies);
 expectType<string[] | undefined>(packageJson.bundledDependencies);
 expectType<PackageJson.Dependency | undefined>(packageJson.resolutions);
 expectType<PackageJson.WorkspaceConfig | string[] | undefined>(packageJson.workspaces);
+expectAssignable<PackageJson['overrides']>({foo: '1.0.0'});
+expectAssignable<PackageJson['overrides']>({foo: {'.': '1.0.0', bar: '1.0.0'}});
+expectAssignable<PackageJson['overrides']>({baz: {bar: {foo: '1.0.0'}}});
+expectAssignable<PackageJson['overrides']>({foo: undefined});
+expectAssignable<PackageJson['overrides']>({foo: {bar: undefined}});
 expectAssignable<PackageJson.DevEngineDependency>({
 	name: 'unicorn',
 	version: '>= 1.0.0',