fix(cli/unstable): promptMultipleSelect() add isTerminal() check

cli/unstable_prompt_multiple_select.ts

@@ -16,6 +16,8 @@ const PADDING = " ".repeat(INDICATOR.length);
 const CHECKED = "◉";
 const UNCHECKED = "◯";
 
+const input = Deno.stdin;
+const output = Deno.stdout;
 const encoder = new TextEncoder();
 const decoder = new TextDecoder();
 
@@ -29,7 +31,7 @@ const SHOW_CURSOR = encoder.encode("\x1b[?25h");
  * @param message The prompt message to show to the user.
  * @param values The values for the prompt.
  * @param options The options for the prompt.
- * @returns The selected values as an array of strings.
+ * @returns The selected values as an array of strings or `null` if stdin is not a TTY.
  *
  * @example Usage
  * ```ts ignore
@@ -42,32 +44,37 @@ export function promptMultipleSelect(
   message: string,
   values: string[],
   options: PromptMultipleSelectOptions = {},
-): string[] {
+): string[] | null {
+  if (!input.isTerminal()) return null;
+
   const { clear } = options;
+
   const length = values.length;
   let selectedIndex = 0;
   const selectedIndexes = new Set<number>();
 
-  Deno.stdin.setRaw(true);
-  Deno.stdout.writeSync(HIDE_CURSOR);
+  input.setRaw(true);
+  output.writeSync(HIDE_CURSOR);
+
   const buffer = new Uint8Array(4);
+
   loop:
   while (true) {
-    Deno.stdout.writeSync(encoder.encode(`${message}\r\n`));
+    output.writeSync(encoder.encode(`${message}\r\n`));
     for (const [index, value] of values.entries()) {
       const selected = index === selectedIndex;
       const start = selected ? INDICATOR : PADDING;
       const checked = selectedIndexes.has(index);
       const state = checked ? CHECKED : UNCHECKED;
-      Deno.stdout.writeSync(encoder.encode(`${start} ${state} ${value}\r\n`));
+      output.writeSync(encoder.encode(`${start} ${state} ${value}\r\n`));
     }
-    const n = Deno.stdin.readSync(buffer);
+    const n = input.readSync(buffer);
     if (n === null || n === 0) break;
-    const input = decoder.decode(buffer.slice(0, n));
+    const string = decoder.decode(buffer.slice(0, n));
 
-    switch (input) {
+    switch (string) {
       case ETX:
-        Deno.stdout.writeSync(SHOW_CURSOR);
+        output.writeSync(SHOW_CURSOR);
         return Deno.exit(0);
       case ARROW_UP:
         selectedIndex = (selectedIndex - 1 + length) % length;
@@ -85,13 +92,16 @@ export function promptMultipleSelect(
         }
         break;
     }
-    Deno.stdout.writeSync(encoder.encode(`\x1b[${length + 1}A`));
+    output.writeSync(encoder.encode(`\x1b[${length + 1}A`));
   }
+
   if (clear) {
-    Deno.stdout.writeSync(encoder.encode(`\x1b[${length + 1}A`));
-    Deno.stdout.writeSync(CLEAR_ALL);
+    output.writeSync(encoder.encode(`\x1b[${length + 1}A`));
+    output.writeSync(CLEAR_ALL);
   }
-  Deno.stdout.writeSync(SHOW_CURSOR);
-  Deno.stdin.setRaw(false);
+
+  output.writeSync(SHOW_CURSOR);
+  input.setRaw(false);
+
   return [...selectedIndexes].map((it) => values[it] as string);
 }

cli/unstable_prompt_multiple_select_test.ts

@@ -9,6 +9,7 @@ const decoder = new TextDecoder();
 
 Deno.test("promptMultipleSelect() handles enter", () => {
   stub(Deno.stdin, "setRaw");
+  stub(Deno.stdin, "isTerminal", () => true);
 
   const expectedOutput = [
     "\x1b[?25l",
@@ -62,6 +63,7 @@ Deno.test("promptMultipleSelect() handles enter", () => {
 
 Deno.test("promptMultipleSelect() handles selection", () => {
   stub(Deno.stdin, "setRaw");
+  stub(Deno.stdin, "isTerminal", () => true);
 
   const expectedOutput = [
     "\x1b[?25l",
@@ -121,6 +123,7 @@ Deno.test("promptMultipleSelect() handles selection", () => {
 
 Deno.test("promptMultipleSelect() handles multiple selection", () => {
   stub(Deno.stdin, "setRaw");
+  stub(Deno.stdin, "isTerminal", () => true);
 
   const expectedOutput = [
     "\x1b[?25l",
@@ -204,6 +207,7 @@ Deno.test("promptMultipleSelect() handles multiple selection", () => {
 
 Deno.test("promptMultipleSelect() handles arrow down", () => {
   stub(Deno.stdin, "setRaw");
+  stub(Deno.stdin, "isTerminal", () => true);
 
   const expectedOutput = [
     "\x1b[?25l",
@@ -275,6 +279,7 @@ Deno.test("promptMultipleSelect() handles arrow down", () => {
 
 Deno.test("promptMultipleSelect() handles arrow up", () => {
   stub(Deno.stdin, "setRaw");
+  stub(Deno.stdin, "isTerminal", () => true);
 
   const expectedOutput = [
     "\x1b[?25l",
@@ -346,6 +351,7 @@ Deno.test("promptMultipleSelect() handles arrow up", () => {
 
 Deno.test("promptMultipleSelect() handles up index overflow", () => {
   stub(Deno.stdin, "setRaw");
+  stub(Deno.stdin, "isTerminal", () => true);
 
   const expectedOutput = [
     "\x1b[?25l",
@@ -411,6 +417,7 @@ Deno.test("promptMultipleSelect() handles up index overflow", () => {
 
 Deno.test("promptMultipleSelect() handles down index overflow", () => {
   stub(Deno.stdin, "setRaw");
+  stub(Deno.stdin, "isTerminal", () => true);
 
   const expectedOutput = [
     "\x1b[?25l",
@@ -489,6 +496,7 @@ Deno.test("promptMultipleSelect() handles down index overflow", () => {
 
 Deno.test("promptMultipleSelect() handles clear option", () => {
   stub(Deno.stdin, "setRaw");
+  stub(Deno.stdin, "isTerminal", () => true);
 
   const expectedOutput = [
     "\x1b[?25l",
@@ -549,6 +557,7 @@ Deno.test("promptMultipleSelect() handles clear option", () => {
 
 Deno.test("promptMultipleSelect() handles ETX", () => {
   stub(Deno.stdin, "setRaw");
+  stub(Deno.stdin, "isTerminal", () => true);
 
   let called = false;
   stub(
@@ -607,3 +616,31 @@ Deno.test("promptMultipleSelect() handles ETX", () => {
   assertEquals(expectedOutput, actualOutput);
   restore();
 });
+
+Deno.test("promptMultipleSelect() returns null if Deno.stdin.isTerminal() is false", () => {
+  stub(Deno.stdin, "setRaw");
+  stub(Deno.stdin, "isTerminal", () => false);
+
+  const expectedOutput: string[] = [];
+
+  const actualOutput: string[] = [];
+
+  stub(
+    Deno.stdout,
+    "writeSync",
+    (data: Uint8Array) => {
+      const output = decoder.decode(data);
+      actualOutput.push(output);
+      return data.length;
+    },
+  );
+
+  const browsers = promptMultipleSelect("Please select browsers:", [
+    "safari",
+    "chrome",
+    "firefox",
+  ]);
+  assertEquals(browsers, null);
+  assertEquals(expectedOutput, actualOutput);
+  restore();
+});