tui: detect array-of-enum on items.enum alone (#1752)

* tui: detect array-of-enum on items.enum alone (#1751)

The TUI schemaToForm array-of-enum branch was nested under an outer
`if (property.enum)` guard, so a standard array-of-enums schema —
`{ type: "array", items: { enum: [...] } }` with no top-level `enum` — never
reached it and fell through to a plain string input. The web SchemaForm already
guards on `items?.enum` alone; this aligns the TUI with it.

Restructure the enum handling so the array-of-enums case keys on
`property.type === "array" && property.items?.enum` independently of a top-level
`enum`, falling back to the single-select `property.enum` branch otherwise. The
enumNames labeling from #1691 applies unchanged.

Tests: the array-of-enum cases now use the standard `items.enum`-only shape
(dropping the redundant top-level `enum` the old nesting required), plus a case
asserting a redundant top-level `enum` still works.

Closes #1751

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5

* docs(pr-screenshots): TUI array-of-enum before/after proof shots (#1751)

Before/after of the TUI tool form for an array-of-enums field with no top-level
`enum`: before the fix it renders as a plain text field (raw "m"); with the fix
it renders as a select resolving the enumNames title ("Medium").

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

clients/tui/__tests__/schemaToForm.test.ts

@@ -57,13 +57,34 @@ describe("schemaToForm", () => {
     });
   });
 
-  it("builds a select field from an array-of-enum", () => {
+  it("builds a select field from an array-of-enum on items.enum alone", () => {
+    const form = schemaToForm(
+      {
+        properties: {
+          // Standard array-of-enums shape: options come from `items.enum` with
+          // NO top-level `enum`. The array branch keys on `items.enum` alone
+          // (matching the web guard), so this renders as a select.
+          tags: {
+            type: "array",
+            items: { enum: ["a", "b"] },
+          },
+        },
+      },
+      "arrayEnum",
+    );
+    expect(form.sections[0]!.fields[0]).toMatchObject({
+      type: "select",
+      options: [
+        { label: "a", value: "a" },
+        { label: "b", value: "b" },
+      ],
+    });
+  });
+
+  it("still builds a select for an array-of-enum that also carries a top-level enum", () => {
     const form = schemaToForm(
       {
         properties: {
-          // The array branch is nested under the outer `enum` guard, so a
-          // top-level `enum` must also be present for it to be reached; the
-          // options are taken from `items.enum`.
           tags: {
             type: "array",
             enum: ["a", "b"],
@@ -71,7 +92,7 @@ describe("schemaToForm", () => {
           },
         },
       },
-      "arrayEnum",
+      "arrayEnumRedundant",
     );
     expect(form.sections[0]!.fields[0]).toMatchObject({
       type: "select",
@@ -133,7 +154,6 @@ describe("schemaToForm", () => {
         properties: {
           pets: {
             type: "array",
-            enum: ["pet-1", "pet-2"],
             items: { enum: ["pet-1", "pet-2"], enumNames: ["Cats", "Dogs"] },
           },
         },
@@ -155,7 +175,6 @@ describe("schemaToForm", () => {
         properties: {
           pets: {
             type: "array",
-            enum: ["pet-1", "pet-2"],
             items: { enum: ["pet-1", "pet-2"], enumNames: ["Cats"] },
           },
         },

clients/tui/src/utils/schemaToForm.ts

@@ -69,27 +69,24 @@ export function schemaToForm(
 
     let field: FormField;
 
-    // Handle enum -> select
-    if (property.enum) {
-      if (property.type === "array" && property.items?.enum) {
-        // For array of enums, we'll use select but handle it differently
-        // Note: ink-form doesn't have multiselect, so we'll use select
-        field = {
-          type: "select",
-          ...baseField,
-          options: toSelectOptions(
-            property.items.enum,
-            property.items.enumNames,
-          ),
-        } as FormField;
-      } else {
-        // Single select
-        field = {
-          type: "select",
-          ...baseField,
-          options: toSelectOptions(property.enum, property.enumNames),
-        } as FormField;
-      }
+    // Handle enum -> select. Detect the array-of-enums case on `items.enum`
+    // alone (matching the web SchemaForm guard) — a standard array-of-enums
+    // schema carries no top-level `enum`, so gating on it would drop the field
+    // to a plain string input.
+    if (property.type === "array" && property.items?.enum) {
+      // ink-form has no multiselect, so we render a single select.
+      field = {
+        type: "select",
+        ...baseField,
+        options: toSelectOptions(property.items.enum, property.items.enumNames),
+      } as FormField;
+    } else if (property.enum) {
+      // Single select
+      field = {
+        type: "select",
+        ...baseField,
+        options: toSelectOptions(property.enum, property.enumNames),
+      } as FormField;
     } else {
       // Map JSON Schema types to ink-form types
       switch (property.type) {

pr-screenshots/README.md

@@ -1,3 +1,31 @@
+# TUI array-of-enum renders as a select on `items.enum` alone (#1751) — proof screenshots
+
+Follow-up to #1691. The TUI `schemaToForm` array-of-enum branch was nested under
+`if (property.enum)`, so a standard array-of-enums schema —
+`{ type: "array", items: { enum, enumNames } }` with **no** top-level `enum` —
+fell through to a plain text input. The fix keys the array case on `items.enum`
+alone (matching the web `SchemaForm`). Captured non-interactively (a standalone
+render of the real `ink-form` built by the real `schemaToForm`).
+
+The demo schema has a `Sizes` array-of-enum field (`enum: [s,m,l]` +
+`enumNames: [Small, Medium, Large]`, `default: "m"`, **no** top-level `enum`)
+and a `Priority` single-enum control (has a top-level `enum`).
+
+![Before #1751 — the array-of-enum field is a plain text input showing the raw default "m"](tui-1751-before-string.png)
+
+**Before the fix** (reproducing the old nesting): `Sizes` is a plain **text
+field** showing the raw default **`m`** — `enumNames` never applies because it
+isn't a select at all.
+
+![With the #1751 fix — the array-of-enum field is a select resolving "m" to its title "Medium"](tui-1751-after-select.png)
+
+**With the fix:** `Sizes` is now a **select**; the default `m` resolves to its
+title **`Medium`**. The `Priority` control (which has a top-level `enum`) shows
+`High` in both — unchanged, confirming the reorder only affects the intended
+`items.enum`-only case.
+
+---
+
 # TUI enum forms honor `enumNames` (#1691) — proof screenshots
 
 The TUI tool-test form (`schemaToForm` → `ink-form`) rendered against a legacy