fix(cli): reject fetch-only output modes in parse mode

src/commands/root.ts

@@ -641,6 +641,7 @@ export async function root(argv: string[]) {
   if (flags.help || _.length === 0) return console.log(rootHelp)
 
   const [src, selector] = _
+  const isUrl = /^https?:\/\//.test(src!)
   const opts = {
     limit: num(flags.limit, 50, { flag: '--limit', kind: 'positive integer', fail }),
     all: flags.all === true,
@@ -722,7 +723,6 @@ export async function root(argv: string[]) {
   }
   const emitStructured = (value: unknown[]) =>
     jsonEnvelope ? emitJsonEnvelope(value, opts) : emitJson(value, opts)
-  const isUrl = /^https?:\/\//.test(src!)
   const envelopeConflict =
     flags.md === true
       ? '--md'
@@ -758,6 +758,14 @@ export async function root(argv: string[]) {
       'use it with --row, --table, --locate, or a selector; fetch mode already returns JSON'
     )
   }
+  const fetchOnlyOutputMode =
+    typeof flags.output === 'string' ? '--output' : flags.body === true ? '--body' : null
+  if (fetchOnlyOutputMode && (!isUrl || selector !== undefined)) {
+    fail(
+      `${fetchOnlyOutputMode} requires fetch mode without a selector`,
+      'use a URL without a selector, or choose a parse output mode'
+    )
+  }
   const headers = isUrl ? requestHeaders(flags) : {}
   const parseFlags =
     selector !== undefined ||

test/cli.test.ts

@@ -590,6 +590,24 @@ test('--where fails outside --row or --table before source I/O', () => {
   expect(r.err).not.toContain('ENOENT')
 })
 
+test('fetch-only output modes fail in parse mode before source I/O', () => {
+  const cases: [string[], string][] = [
+    [['missing.html', '.x', '--body'], '--body'],
+    [['http://127.0.0.1:1', '.x', '--body'], '--body'],
+    [['missing.html', '--body'], '--body'],
+    [['missing.html', '.x', '--output', 'out.bin'], '--output'],
+    [['missing.html', '.x', '-o', 'out.bin'], '--output'],
+  ]
+
+  for (const [args, outputMode] of cases) {
+    const r = ax(args)
+    expect(r.code).toBe(1)
+    expect(r.out).toBe('')
+    expect(r.err).toContain(`ax: error: ${outputMode} requires fetch mode without a selector`)
+    expect(r.err).not.toContain('ENOENT')
+  }
+})
+
 test('cap: default limit with stderr note', () => {
   const r = ax(['many.html', '.x'])
   expect(r.out.split('\n')).toHaveLength(50)