fix(mobile): give the PR Review paste control a visible result on every tap

apps/mobile/src/components/pr-review/pr-review-entry-screen-paste-read.test.ts

@@ -0,0 +1,57 @@
+// The paste control runs a fire-and-forget press handler, so a clipboard read
+// the platform refuses must still end in a visible result. These cases live
+// apart from the URL-field suite to keep both files within the lint line cap.
+
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+import {
+  find,
+  flush,
+  mocks,
+  propsOf,
+  renderLoaded,
+  resetHookSlots,
+} from './pr-review-entry-screen-test-utils';
+
+beforeEach(() => {
+  vi.clearAllMocks();
+  resetHookSlots();
+  mocks.clipboard.current = '';
+  mocks.clipboardHasString.current = false;
+  mocks.clipboardFailure.current = null;
+  mocks.clipboardHasStringFailure.current = null;
+});
+
+function pasteControl(tree: unknown) {
+  return find(
+    tree,
+    'Pressable',
+    p => p.accessibilityLabel === 'Paste pull request or merge request link'
+  );
+}
+
+describe('paste clipboard read failures', () => {
+  it('reports a refused read instead of leaving the tap without a result', async () => {
+    mocks.clipboardFailure.current = new Error('clipboard unavailable');
+    const tree = await renderLoaded();
+    await (propsOf(pasteControl(tree)).onPress as () => Promise<void>)();
+    await flush();
+    expect(mocks.toastError).toHaveBeenCalledWith(
+      'Paste access was denied. Allow paste and try again.'
+    );
+    expect(mocks.toastError).toHaveBeenCalledTimes(1);
+    expect(mocks.push).not.toHaveBeenCalled();
+  });
+
+  it('reports the same denial when only the text probe fails', async () => {
+    mocks.clipboardHasStringFailure.current = new Error('clipboard unavailable');
+    const tree = await renderLoaded();
+    await (propsOf(pasteControl(tree)).onPress as () => Promise<void>)();
+    await flush();
+    expect(mocks.toastError).toHaveBeenCalledWith(
+      'Paste access was denied. Allow paste and try again.'
+    );
+    expect(mocks.toastError).not.toHaveBeenCalledWith('Clipboard is empty');
+    expect(mocks.push).not.toHaveBeenCalled();
+  });
+});

apps/mobile/src/components/pr-review/pr-review-entry-screen-test-utils.ts

@@ -23,6 +23,10 @@ const harnessMocks = vi.hoisted(() => ({
   toastError: vi.fn(),
   clipboard: { current: '' as string },
   clipboardHasString: { current: false },
+  // A clipboard read the platform refuses: the mocks below throw these so a
+  // test can prove the tap still ends in a visible result.
+  clipboardFailure: { current: null as Error | null },
+  clipboardHasStringFailure: { current: null as Error | null },
 }));
 
 // A hoisted binding cannot be exported directly; alias it for the test files.
@@ -53,10 +57,16 @@ vi.mock('expo-router', () => ({
 vi.mock('expo-clipboard', () => ({
   getStringAsync: async () => {
     await Promise.resolve();
+    if (harnessMocks.clipboardFailure.current) {
+      throw harnessMocks.clipboardFailure.current;
+    }
     return harnessMocks.clipboard.current;
   },
   hasStringAsync: async () => {
     await Promise.resolve();
+    if (harnessMocks.clipboardHasStringFailure.current) {
+      throw harnessMocks.clipboardHasStringFailure.current;
+    }
     return harnessMocks.clipboardHasString.current;
   },
 }));

apps/mobile/src/components/pr-review/pr-review-entry-screen.tsx

@@ -24,11 +24,10 @@ import { ICON_TARGET_BOX_CLASS } from '@/lib/a11y/tap-target';
 import { useThemeColors } from '@/lib/hooks/use-theme-colors';
 import { providerPrRefLabel, providerPrRoutePath } from '@/lib/pr-review/provider-pr-ref';
 import {
-  decidePrLinkPaste,
   prLinkToastClipboardEmptyCopy,
   prLinkToastPasteDeniedCopy,
+  readPrLinkPasteClipboard,
   selectPrLinkClearButtonVisible,
-  selectPrLinkPasteEmptyReason,
 } from '@/lib/pr-review/pr-link-paste';
 import {
   getRecentPrs,
@@ -92,22 +91,22 @@ export function PrReviewEntryScreen() {
   };
 
   const handlePaste = async () => {
-    const clipboard = await Clipboard.getStringAsync();
-    const decision = decidePrLinkPaste(clipboard);
-    if (decision.kind === 'empty') {
-      // iOS answers a denied prompt with an empty read, so ask the prompt-free
-      // probe whether the clipboard still holds text before calling it empty.
-      const clipboardHasString = await Clipboard.hasStringAsync();
+    // Every tap ends in a visible result: the field is replaced, or a toast
+    // names why nothing could be pasted. The reader never rejects, so a
+    // refused or broken clipboard read cannot vanish into the press handler.
+    const outcome = await readPrLinkPasteClipboard(Clipboard);
+    if (outcome.kind === 'empty') {
+      // iOS answers a denied prompt with an empty read, so the reader asks the
+      // prompt-free probe whether the clipboard still holds text before calling
+      // it empty; a read that failed outright reports the same denial.
       announcingToast.error(
-        selectPrLinkPasteEmptyReason(clipboard, clipboardHasString) === 'denied'
-          ? prLinkToastPasteDeniedCopy()
-          : prLinkToastClipboardEmptyCopy()
+        outcome.reason === 'denied' ? prLinkToastPasteDeniedCopy() : prLinkToastClipboardEmptyCopy()
       );
       return;
     }
     // Replace the native field, ref and derived UI together, never append at the cursor.
-    writeField(decision.text);
-    if (decision.kind === 'non-url-text') {
+    writeField(outcome.text);
+    if (outcome.kind === 'non-url-text') {
       return;
     }
     handleSubmit();

apps/mobile/src/lib/pr-review/pr-link-paste.test.ts

@@ -5,6 +5,7 @@ import {
   decidePrLinkPaste,
   prLinkToastClipboardEmptyCopy,
   prLinkToastPasteDeniedCopy,
+  readPrLinkPasteClipboard,
   selectPrLinkClearButtonVisible,
   selectPrLinkPasteEmptyReason,
 } from './pr-link-paste';
@@ -137,6 +138,63 @@ describe('selectPrLinkPasteEmptyReason', () => {
   });
 });
 
+describe('readPrLinkPasteClipboard', () => {
+  const reader = (text: string | null, hasString: boolean) => ({
+    getStringAsync: async () => {
+      await Promise.resolve();
+      return text;
+    },
+    hasStringAsync: async () => {
+      await Promise.resolve();
+      return hasString;
+    },
+  });
+
+  it('hands a resolvable read to the paste decision', async () => {
+    const url = 'https://github.com/octocat/hello-world/pull/42';
+    await expect(readPrLinkPasteClipboard(reader(url, true))).resolves.toEqual({
+      kind: 'valid-pr-url',
+      text: url,
+    });
+    await expect(readPrLinkPasteClipboard(reader('  not a link  ', true))).resolves.toEqual({
+      kind: 'non-url-text',
+      text: 'not a link',
+    });
+  });
+
+  it('names an empty clipboard as empty', async () => {
+    await expect(readPrLinkPasteClipboard(reader('', false))).resolves.toEqual({
+      kind: 'empty',
+      reason: 'empty',
+    });
+  });
+
+  it('reports a declined paste prompt as a denial', async () => {
+    await expect(readPrLinkPasteClipboard(reader('', true))).resolves.toEqual({
+      kind: 'empty',
+      reason: 'denied',
+    });
+  });
+
+  it('turns a rejected text read into the denied result instead of rejecting', async () => {
+    await expect(
+      readPrLinkPasteClipboard({
+        getStringAsync: () => Promise.reject(new Error('clipboard unavailable')),
+        hasStringAsync: () => Promise.resolve(false),
+      })
+    ).resolves.toEqual({ kind: 'empty', reason: 'denied' });
+  });
+
+  it('turns a rejected text probe into the denied result instead of rejecting', async () => {
+    await expect(
+      readPrLinkPasteClipboard({
+        getStringAsync: () => Promise.resolve(''),
+        hasStringAsync: () => Promise.reject(new Error('clipboard unavailable')),
+      })
+    ).resolves.toEqual({ kind: 'empty', reason: 'denied' });
+  });
+});
+
 describe('selectPrLinkClearButtonVisible', () => {
   it('is present when the field has content', () => {
     expect(selectPrLinkClearButtonVisible({ hasInput: true })).toBe(true);

apps/mobile/src/lib/pr-review/pr-link-paste.ts

@@ -67,6 +67,69 @@ export function selectPrLinkPasteEmptyReason(
   return (clipboard ?? '').length === 0 && clipboardHasString ? 'denied' : 'empty';
 }
 
+type PrLinkPasteClipboardReader = {
+  getStringAsync: () => Promise<string | null | undefined>;
+  hasStringAsync: () => Promise<boolean>;
+};
+
+/**
+ * A paste tap's clipboard outcome. `empty` carries why the read produced
+ * nothing, so the call site picks the toast that names it; every other kind
+ * carries the text to write into the field.
+ */
+export type PrLinkPasteOutcome =
+  | { kind: 'valid-pr-url'; text: string }
+  | { kind: 'non-url-text'; text: string }
+  | { kind: 'empty'; reason: PrLinkPasteEmptyReason };
+
+/**
+ * Read the clipboard for a paste tap without ever rejecting.
+ *
+ * The control runs this as a fire-and-forget press handler, so a rejected
+ * read would leave the tap with no visible result at all: no text, no
+ * validation, no toast. A read the platform refuses — the iOS paste prompt
+ * declined, a service that is not available, a throw out of the native
+ * module — is reported as `denied`, the state whose copy already tells the
+ * reader that paste access was refused and asks them to try again. The
+ * clipboard-empty answer keeps its own copy through
+ * `selectPrLinkPasteEmptyReason`, so a resolver that throws on the second
+ * probe cannot swallow the tap either.
+ *
+ * The attachment helpers (`readClipboardText`, `hasClipboardText`) also
+ * swallow a failed read, but they collapse it into `''`/`false`, which this
+ * control cannot use: it has to tell a refused read from a clipboard that is
+ * genuinely empty to pick the copy that names the right cause.
+ */
+export async function readPrLinkPasteClipboard(
+  reader: PrLinkPasteClipboardReader
+): Promise<PrLinkPasteOutcome> {
+  const textRead = await settleClipboardRead(() => reader.getStringAsync());
+  if (!textRead.ok) {
+    return { kind: 'empty', reason: 'denied' };
+  }
+  const clipboard = textRead.value ?? '';
+  const decision = decidePrLinkPaste(clipboard);
+  if (decision.kind !== 'empty') {
+    return decision;
+  }
+  const probe = await settleClipboardRead(() => reader.hasStringAsync());
+  if (!probe.ok) {
+    return { kind: 'empty', reason: 'denied' };
+  }
+  return { kind: 'empty', reason: selectPrLinkPasteEmptyReason(clipboard, probe.value) };
+}
+
+/** One clipboard read, with a refusal reported as data instead of a rejection. */
+async function settleClipboardRead<T>(
+  read: () => Promise<T>
+): Promise<{ ok: true; value: T } | { ok: false }> {
+  try {
+    return { ok: true, value: await read() };
+  } catch {
+    return { ok: false };
+  }
+}
+
 /** Toast copy when paste finds an empty clipboard. */
 export function prLinkToastClipboardEmptyCopy(): string {
   return i18n.t('prReview.linkPasteClipboardEmpty');