test(tui): drive the ink-form patch through the plugin, and drop the esbuild type import

Review follow-ups on #1983.

The patch's tests called the string helper directly, so nothing exercised
the esbuild `onLoad` filter that decides whether the helper runs at all. A
filter that stopped matching would leave the build green, the tests green,
and the typo shipped — the silent no-op the throwing helper exists to
prevent, reintroduced one level up. The plugin is now driven the way
esbuild drives it (register, then invoke) against the real `ink-form`
module path, and a second test pins the filter's scope: it matches that
path and a Windows-separator one, and rejects `Form.js`,
`ink-select-input`'s own `SubmitButton.js`, and a first-party
`src/SubmitButton.jsx`.

The plugin type came from `import type { Plugin } from "esbuild"`, but
`esbuild` is tsup's transitive dependency, not one this client declares —
it typechecked only while npm happened to hoist it, and would break on a
lock change that nested it. Derive it from tsup's own
`Options["esbuildPlugins"]` instead of adding a dependency for a type.

Closes #1952

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WLYmVPVLdeYpE6aMTUsCks

clients/tui/__tests__/tsupConfig.test.ts

@@ -27,7 +27,9 @@ import { fileURLToPath } from "node:url";
 import type { Options } from "tsup";
 import tsupConfig, {
   INK_FORM_INCOMPLETE_HINT,
+  INK_FORM_SUBMIT_BUTTON,
   fixInkFormIncompleteHint,
+  inkFormLabelPatch,
 } from "../tsup.config.js";
 
 const clientDir = path.resolve(
@@ -86,6 +88,15 @@ function reactRenderingDependencies(): string[] {
   );
 }
 
+/** The real `ink-form` module the label patch targets. */
+const submitButtonPath = path.join(
+  clientDir,
+  "node_modules",
+  "ink-form",
+  "lib",
+  "SubmitButton.js",
+);
+
 const config = singleConfig(tsupConfig);
 const noExternal = stringEntries(config.noExternal);
 const external = stringEntries(config.external);
@@ -127,22 +138,64 @@ describe("tui tsup config", () => {
     // Read the real dependency, so an `ink-form` upgrade that fixes or rewords
     // the label fails here — the patch must then be removed, not left silently
     // matching nothing.
-    const submitButton = readFileSync(
+    const patched = fixInkFormIncompleteHint(
-      path.join(
+      readFileSync(submitButtonPath, "utf8"),
-        clientDir,
+      submitButtonPath,
-        "node_modules",
-        "ink-form",
-        "lib",
-        "SubmitButton.js",
-      ),
-      "utf8",
     );
-
-    const patched = fixInkFormIncompleteHint(submitButton, "SubmitButton.js");
     expect(patched).toContain(INK_FORM_INCOMPLETE_HINT.fixed);
     expect(patched).not.toContain(INK_FORM_INCOMPLETE_HINT.typo);
   });
 
+  it("routes the real module through the plugin, not just the helper", async () => {
+    // The helper is only reached if the plugin's onLoad filter matches. Drive
+    // the plugin as esbuild would — register, then invoke — so a filter that
+    // stops matching the real module's path fails here instead of no-opping
+    // through a green build (the exact silence this patch exists to prevent).
+    type OnLoadCallback = (args: {
+      path: string;
+    }) => Promise<{ contents: string }>;
+    const registered: { filter: RegExp; callback: OnLoadCallback }[] = [];
+
+    const build = {
+      onLoad: (options: { filter: RegExp }, callback: OnLoadCallback) =>
+        registered.push({ filter: options.filter, callback }),
+    };
+    // esbuild's `PluginBuild` carries far more than this patch touches, and the
+    // stub above deliberately implements only the one hook it registers — so
+    // the double cast is bridging a real structural gap, not hiding a mismatch.
+    // A hook the patch called but the stub lacks fails as undefined here rather
+    // than passing silently.
+    inkFormLabelPatch.setup(
+      build as unknown as Parameters<typeof inkFormLabelPatch.setup>[0],
+    );
+
+    expect(registered).toHaveLength(1);
+    const [{ filter, callback }] = registered;
+    expect(filter.test(submitButtonPath)).toBe(true);
+
+    const { contents } = await callback({ path: submitButtonPath });
+    expect(contents).toContain(INK_FORM_INCOMPLETE_HINT.fixed);
+    expect(contents).not.toContain(INK_FORM_INCOMPLETE_HINT.typo);
+  });
+
+  it("scopes the patch to ink-form's SubmitButton and nothing else", () => {
+    expect(INK_FORM_SUBMIT_BUTTON.test(submitButtonPath)).toBe(true);
+    // A Windows-style path must match too — the filter runs against whatever
+    // esbuild resolved, and its separator is the platform's.
+    expect(
+      INK_FORM_SUBMIT_BUTTON.test(
+        "C:\\repo\\node_modules\\ink-form\\lib\\SubmitButton.js",
+      ),
+    ).toBe(true);
+    for (const other of [
+      "/repo/node_modules/ink-form/lib/Form.js",
+      "/repo/node_modules/ink-select-input/build/SubmitButton.js",
+      "/repo/src/SubmitButton.jsx",
+    ]) {
+      expect(INK_FORM_SUBMIT_BUTTON.test(other), other).toBe(false);
+    }
+  });
+
   it("fails loudly rather than silently skipping a label it cannot find", () => {
     expect(() =>
       fixInkFormIncompleteHint("no such label here", "SubmitButton.js"),

clients/tui/tsup.config.ts

@@ -1,5 +1,4 @@
-import { defineConfig } from "tsup";
+import { defineConfig, type Options } from "tsup";
-import type { Plugin } from "esbuild";
 import { readFile } from "node:fs/promises";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
@@ -45,11 +44,25 @@ export function fixInkFormIncompleteHint(source: string, file: string): string {
   );
 }
 
-const inkFormLabelPatch: Plugin = {
+/**
+ * Which module the patch above is applied to.
+ *
+ * Exported so the tests can check it against the *resolved* path of the real
+ * `ink-form` module — a filter that stops matching is the one way this patch
+ * can silently no-op, since `fixInkFormIncompleteHint` would then never run.
+ */
+export const INK_FORM_SUBMIT_BUTTON = /ink-form[\\/]lib[\\/]SubmitButton\.js$/;
+
+// The plugin type is derived from tsup rather than imported from `esbuild`:
+// `esbuild` is tsup's transitive dependency, not a declared one of this client,
+// so a direct import typechecks only while npm happens to hoist it.
+type EsbuildPlugin = NonNullable<Options["esbuildPlugins"]>[number];
+
+export const inkFormLabelPatch: EsbuildPlugin = {
   name: "ink-form-label-patch",
   setup(build) {
     build.onLoad(
-      { filter: /ink-form[\\/]lib[\\/]SubmitButton\.js$/ },
+      { filter: INK_FORM_SUBMIT_BUTTON },
       async ({ path: file }) => ({
         contents: fixInkFormIncompleteHint(await readFile(file, "utf8"), file),
         loader: "js",