fix(cli): include allowed values in oneOf const validation errors

apps/cli/src/__tests__/lib/validate-type-spec.test.ts

@@ -0,0 +1,84 @@
+import { describe, expect, test } from 'bun:test';
+import { validateValueAgainstTypeSpec } from '../../lib/operation-args';
+import { CliError } from '../../lib/errors';
+import type { CliTypeSpec } from '../../cli/types';
+
+describe('validateValueAgainstTypeSpec – oneOf const enumeration', () => {
+  const schema: CliTypeSpec = {
+    oneOf: [
+      { const: 'headerRow' },
+      { const: 'totalRow' },
+      { const: 'firstColumn' },
+      { const: 'lastColumn' },
+      { const: 'bandedRows' },
+      { const: 'bandedColumns' },
+    ],
+  };
+
+  test('accepts a valid const value', () => {
+    expect(() => validateValueAgainstTypeSpec('headerRow', schema, 'flag')).not.toThrow();
+    expect(() => validateValueAgainstTypeSpec('bandedColumns', schema, 'flag')).not.toThrow();
+  });
+
+  test('rejects an invalid value and lists all allowed values', () => {
+    try {
+      validateValueAgainstTypeSpec('lastRow', schema, 'tables set-style-option:flag');
+      throw new Error('Expected CliError to be thrown');
+    } catch (error) {
+      expect(error).toBeInstanceOf(CliError);
+      const cliError = error as CliError;
+      expect(cliError.code).toBe('VALIDATION_ERROR');
+      expect(cliError.message).toBe(
+        'tables set-style-option:flag must be one of: headerRow, totalRow, firstColumn, lastColumn, bandedRows, bandedColumns.',
+      );
+    }
+  });
+
+  test('preserves per-variant errors in details', () => {
+    try {
+      validateValueAgainstTypeSpec('invalid', schema, 'flag');
+      throw new Error('Expected CliError to be thrown');
+    } catch (error) {
+      const cliError = error as CliError;
+      const details = cliError.details as { errors: string[] };
+      expect(details.errors).toBeArrayOfSize(6);
+    }
+  });
+});
+
+describe('validateValueAgainstTypeSpec – oneOf with mixed schemas', () => {
+  const mixedSchema: CliTypeSpec = {
+    oneOf: [{ const: 'block' }, { type: 'object', properties: { kind: { const: 'inline' } }, required: ['kind'] }],
+  };
+
+  test('falls back to generic message when variants are not all const', () => {
+    try {
+      validateValueAgainstTypeSpec('nope', mixedSchema, 'target');
+      throw new Error('Expected CliError to be thrown');
+    } catch (error) {
+      const cliError = error as CliError;
+      expect(cliError.message).toBe('target must match one of the allowed schema variants.');
+    }
+  });
+});
+
+describe('validateValueAgainstTypeSpec – enum branch', () => {
+  const enumSchema: CliTypeSpec = {
+    type: 'string',
+    enum: ['direct', 'tracked'],
+  } as CliTypeSpec & { enum: string[] };
+
+  test('accepts a valid enum value', () => {
+    expect(() => validateValueAgainstTypeSpec('direct', enumSchema, 'changeMode')).not.toThrow();
+  });
+
+  test('rejects an invalid enum value with allowed list', () => {
+    try {
+      validateValueAgainstTypeSpec('bogus', enumSchema, 'changeMode');
+      throw new Error('Expected CliError to be thrown');
+    } catch (error) {
+      const cliError = error as CliError;
+      expect(cliError.message).toBe('changeMode must be one of: direct, tracked.');
+    }
+  });
+});

apps/cli/src/lib/operation-args.ts

@@ -100,6 +100,19 @@ function acceptsLegacyTextAddressTarget(
   return docApiId === 'replace' || docApiId === 'delete' || docApiId?.startsWith('format.') === true;
 }
 
+/**
+ * If every variant in a `oneOf` is a `{ const: X }`, return the values as strings.
+ * Returns an empty array when the pattern doesn't hold (mixed / nested schemas).
+ */
+function extractConstValues(variants: CliTypeSpec[]): string[] {
+  const values: string[] = [];
+  for (const variant of variants) {
+    if (!('const' in variant)) return [];
+    values.push(String(variant.const));
+  }
+  return values;
+}
+
 export function validateValueAgainstTypeSpec(value: unknown, schema: CliTypeSpec, path: string): void {
   if ('const' in schema) {
     if (value !== schema.const) {
@@ -119,7 +132,13 @@ export function validateValueAgainstTypeSpec(value: unknown, schema: CliTypeSpec
         errors.push(error instanceof Error ? error.message : String(error));
       }
     }
-    throw new CliError('VALIDATION_ERROR', `${path} must match one of the allowed schema variants.`, { errors });
+
+    const allowedValues = extractConstValues(variants);
+    const message =
+      allowedValues.length > 0
+        ? `${path} must be one of: ${allowedValues.join(', ')}.`
+        : `${path} must match one of the allowed schema variants.`;
+    throw new CliError('VALIDATION_ERROR', message, { errors });
   }
 
   if (schema.type === 'json') return;