feat: validate intentional post requests

src/features/posts/inputs.test.ts

@@ -0,0 +1,41 @@
+import { describe, expect, it } from 'vitest'
+import { buildSearchQuery, normalizeUserTarget } from './inputs'
+
+describe('normalizeUserTarget', () => {
+  it.each([
+    ['@tan_stack', 'tan_stack'],
+    ['tan_stack', 'tan_stack'],
+    ['https://x.com/tan_stack', 'tan_stack'],
+    ['https://twitter.com/tan_stack/', 'tan_stack'],
+  ])('normalizes %s', (input, expected) => {
+    expect(normalizeUserTarget(input)).toBe(expected)
+  })
+
+  it.each([
+    '',
+    'not valid',
+    'https://example.com/tan_stack',
+    'https://x.com/tan_stack/status/1',
+  ])('rejects %s', (input) => {
+    expect(() => normalizeUserTarget(input)).toThrow()
+  })
+})
+
+describe('buildSearchQuery', () => {
+  it('keeps a deliberate query unchanged', () => {
+    expect(buildSearchQuery('  AI lang:ja  ', false)).toBe('AI lang:ja')
+  })
+
+  it('adds the follows operator once', () => {
+    expect(buildSearchQuery('AI lang:ja', true)).toBe(
+      'AI lang:ja filter:follows',
+    )
+    expect(buildSearchQuery('AI filter:follows', true)).toBe(
+      'AI filter:follows',
+    )
+  })
+
+  it('rejects an empty query', () => {
+    expect(() => buildSearchQuery('   ', false)).toThrow()
+  })
+})