Set default streams in StdinContext, StdoutContext and `StderrCon…

…text`

src/components/StderrContext.ts

@@ -1,10 +1,11 @@
+import process from 'node:process';
 import {createContext} from 'react';
 
 export type Props = {
 	/**
 	 * Stderr stream passed to `render()` in `options.stderr` or `process.stderr` by default.
 	 */
-	readonly stderr?: NodeJS.WriteStream;
+	readonly stderr: NodeJS.WriteStream;
 
 	/**
 	 * Write any string to stderr, while preserving Ink's output.
@@ -19,7 +20,7 @@ export type Props = {
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention
 const StderrContext = createContext<Props>({
-	stderr: undefined,
+	stderr: process.stderr,
 	write() {}
 });
 

src/components/StdinContext.ts

@@ -1,10 +1,11 @@
+import process from 'node:process';
 import {createContext} from 'react';
 
 export type Props = {
 	/**
 	 * Stdin stream passed to `render()` in `options.stdin` or `process.stdin` by default. Useful if your app needs to handle user input.
 	 */
-	readonly stdin?: NodeJS.ReadStream;
+	readonly stdin: NodeJS.ReadStream;
 
 	/**
 	 * Ink exposes this function via own `<StdinContext>` to be able to handle Ctrl+C, that's why you should use Ink's `setRawMode` instead of `process.stdin.setRawMode`.
@@ -25,7 +26,7 @@ export type Props = {
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention
 const StdinContext = createContext<Props>({
-	stdin: undefined,
+	stdin: process.stdin,
 	setRawMode() {},
 	isRawModeSupported: false,
 	// eslint-disable-next-line @typescript-eslint/naming-convention

src/components/StdoutContext.ts

@@ -1,10 +1,11 @@
+import process from 'node:process';
 import {createContext} from 'react';
 
 export type Props = {
 	/**
 	 * Stdout stream passed to `render()` in `options.stdout` or `process.stdout` by default.
 	 */
-	readonly stdout?: NodeJS.WriteStream;
+	readonly stdout: NodeJS.WriteStream;
 
 	/**
 	 * Write any string to stdout, while preserving Ink's output.
@@ -19,7 +20,7 @@ export type Props = {
  */
 // eslint-disable-next-line @typescript-eslint/naming-convention
 const StdoutContext = createContext<Props>({
-	stdout: undefined,
+	stdout: process.stdout,
 	write() {}
 });