Convert SpawnSyncReturns to a discriminated union

KSXGitHub · KSXGitHub · commit 58aed8ac63d2 · 2018-05-15T07:42:24.000Z
diff --git a/types/node/index.d.ts b/types/node/index.d.ts
@@ -2331,14 +2331,27 @@ declare module "child_process" {
     export interface SpawnSyncOptionsWithBufferEncoding extends SpawnSyncOptions {
         encoding: string; // specify `null`.
     }
-    export interface SpawnSyncReturns<T> {
-        pid: number;
-        output: [T | null, T | null, T | null] | null;
-        stdout: T | null;
-        stderr: T | null;
-        status: number | null;
-        signal: string | null;
-        error: Error | null;
+    export type SpawnSyncOptions = SpawnSyncReturns.WithError | SpawnSyncOptions.WithoutError<T>;
+    export namespace SpawnSyncReturns {
+        export interface Base {
+            pid: number;
+        }
+        export interface WithError extends Base {
+            error: Error;
+            output: null;
+            stdout: null;
+            stderr: null;
+            status: null;
+            signal: null;
+        }
+        export interface WithoutError<T> extends Base {
+            error: null;
+            output: [T | null, T | null, T | null];
+            stdout: T;
+            stderr: T;
+            status: number;
+            signal: string;
+        }
     }
     export function spawnSync(command: string): SpawnSyncReturns<Buffer>;
     export function spawnSync(command: string, options?: SpawnSyncOptionsWithStringEncoding): SpawnSyncReturns<string>;
diff --git a/types/node/v8/index.d.ts b/types/node/v8/index.d.ts
@@ -2243,14 +2243,27 @@ declare module "child_process" {
     export interface SpawnSyncOptionsWithBufferEncoding extends SpawnSyncOptions {
         encoding: string; // specify `null`.
     }
-    export interface SpawnSyncReturns<T> {
-        pid: number;
-        output: [T | null, T | null, T | null] | null;
-        stdout: T | null;
-        stderr: T | null;
-        status: number | null;
-        signal: string | null;
-        error: Error | null;
+    export type SpawnSyncOptions = SpawnSyncReturns.WithError | SpawnSyncOptions.WithoutError<T>;
+    export namespace SpawnSyncReturns {
+        export interface Base {
+            pid: number;
+        }
+        export interface WithError extends Base {
+            error: Error;
+            output: null;
+            stdout: null;
+            stderr: null;
+            status: null;
+            signal: null;
+        }
+        export interface WithoutError<T> extends Base {
+            error: null;
+            output: [T | null, T | null, T | null];
+            stdout: T;
+            stderr: T;
+            status: number;
+            signal: string;
+        }
     }
     export function spawnSync(command: string): SpawnSyncReturns<Buffer>;
     export function spawnSync(command: string, options?: SpawnSyncOptionsWithStringEncoding): SpawnSyncReturns<string>;
diff --git a/types/node/v9/index.d.ts b/types/node/v9/index.d.ts
@@ -2323,14 +2323,27 @@ declare module "child_process" {
     export interface SpawnSyncOptionsWithBufferEncoding extends SpawnSyncOptions {
         encoding: string; // specify `null`.
     }
-    export interface SpawnSyncReturns<T> {
-        pid: number;
-        output: [T | null, T | null, T | null] | null;
-        stdout: T | null;
-        stderr: T | null;
-        status: number | null;
-        signal: string | null;
-        error: Error | null;
+    export type SpawnSyncOptions = SpawnSyncReturns.WithError | SpawnSyncOptions.WithoutError<T>;
+    export namespace SpawnSyncReturns {
+        export interface Base {
+            pid: number;
+        }
+        export interface WithError extends Base {
+            error: Error;
+            output: null;
+            stdout: null;
+            stderr: null;
+            status: null;
+            signal: null;
+        }
+        export interface WithoutError<T> extends Base {
+            error: null;
+            output: [T | null, T | null, T | null];
+            stdout: T;
+            stderr: T;
+            status: number;
+            signal: string;
+        }
     }
     export function spawnSync(command: string): SpawnSyncReturns<Buffer>;
     export function spawnSync(command: string, options?: SpawnSyncOptionsWithStringEncoding): SpawnSyncReturns<string>;
