code-yank

1import { atom, read, update } from 'claude-code'
2import type { EngineInterface, Register, RenderSurface } from 'claude-code'
3
4import type { CodeBlock } from '../types'
5import { describeBlock } from '../core/codeblocks'
6import { findLastReplyBlocks } from './blocks'
7
8const PANE = 'code-yank'
9const HOTKEYS = '123456789abcdefghijklmnopqrstuvwxyz'
10const blocks = atom({ plugin: 'code-yank', key: 'blocks' } as const, [])
11
12export const register: Register = on => {
13  on('session.start', async ($, e, next) => {
14    await $.command.register({
15      name: 'yank',
16      description: 'Copy a code block of the last reply to the clipboard',
17      argumentHint: '[number]',
18    })
19
20    return next(e)
21  })
22
23  on('command.run', { command: 'yank' }, async ($, e) => {
24    const messages = await $.session.messages({})
25    if (!Array.isArray(messages)) return { text: `Cannot read the conversation: ${messages.deny}` }
26
27    const found = findLastReplyBlocks(messages)
28    if (found.length === 0) return { text: 'The last reply has no code blocks.' }
29
30    const chosen = e.args.trim() === '' ? undefined : found[Number.parseInt(e.args, 10) - 1]
31    if (e.args.trim() !== '' && chosen === undefined) return { text: `There is no code block ${e.args.trim()}. The last reply has ${found.length}.` }
32    if (chosen !== undefined) return { text: await copyBlock($, chosen) }
33    if (found.length === 1) return { text: await copyBlock($, found[0] as CodeBlock) }
34
35    await update($, blocks, () => found)
36
37    await $.ui.open({ id: PANE, title: 'Yank', focus: true, closeOnEscape: true, rows: Math.min(found.length, HOTKEYS.length) + 1 })
38
39    return { text: `${found.length} code blocks. Press a key to copy one.` }
40  })
41
42  on('ui.render', { component: 'Pane', requestId: PANE }, async ($, e) => {
43    const { Box, Button, Text } = $.ui.resolve(e)
44    const list = (await read($, blocks)).slice(0, HOTKEYS.length)
45    const width = Math.max(20, (e.props.bodyColumns ?? 80) - 6)
46
47    return (
48      <Box flexDirection="column">
49        {list.map((block, index) => (
50          <Box key={`row-${index}`}>
51            <Button
52              key={`copy-${index}`}
53              plain
54              hotkey={HOTKEYS[index]}
55              label={describeBlock(block).slice(0, width)}
56              autoFocus={index === 0 ? true : undefined}
57              onPress={async () => {
58                $.ui.toast(await copyBlock($, block, e.surface))
59                await $.ui.close({ id: PANE })
60              }}
61            />
62          </Box>
63        ))}
64        {list.length === 0 && <Text dimColor>No code blocks.</Text>}
65      </Box>
66    )
67  })
68}
69
70async function copyBlock($: EngineInterface, block: CodeBlock, surface?: RenderSurface): Promise<string> {
71  const copied = await $.ui.copy({ text: block.source, surface })
72
73  return copied.isCopied ? `Copied: ${describeBlock(block)}` : `Copy failed: ${copied.reason}`
74}
75

1import type { CodeBlock } from '../types'
2
3const FENCE = /^([ \t]*)(`{3,}|~{3,})([^\n`]*)\n([\s\S]*?)\n[ \t]*\2[ \t]*$/gm
4
5export function parseCodeBlocks(text: string): CodeBlock[] {
6  return [...text.matchAll(FENCE)].map(match => ({
7    language: (match[3] ?? '').trim().split(/\s+/)[0] ?? '',
8    source: stripIndent(match[4] ?? '', match[1] ?? ''),
9  }))
10}
11
12export function describeBlock(block: CodeBlock): string {
13  const firstLine = block.source.split('\n').find(line => line.trim() !== '')?.trim() ?? ''
14  const lineCount = block.source.split('\n').length
15  const language = block.language === '' ? 'text' : block.language
16
17  return `${language}, ${lineCount} ${lineCount === 1 ? 'line' : 'lines'}: ${firstLine}`
18}
19
20function stripIndent(source: string, indent: string): string {
21  if (indent === '') return source
22
23  return source
24    .split('\n')
25    .map(line => (line.startsWith(indent) ? line.slice(indent.length) : line))
26    .join('\n')
27}
28

1import type { SessionMessage } from 'claude-code'
2
3import type { CodeBlock } from '../types'
4import { parseCodeBlocks } from '../core/codeblocks'
5
6export function findLastReplyBlocks(messages: readonly SessionMessage[]): CodeBlock[] {
7  const blocks: CodeBlock[] = []
8
9  for (let index = messages.length - 1; index >= 0; index--) {
10    const message = messages[index]
11    if (message === undefined) continue
12    if (message.role === 'user' && message.text !== '' && (message.toolResults ?? []).length === 0) {
13      if (blocks.length > 0) break
14      continue
15    }
16    if (message.role === 'assistant') blocks.unshift(...parseCodeBlocks(message.text))
17  }
18
19  return blocks
20}
21

1export type CodeBlock = { language: string; source: string }
2
3declare module 'claude-code' {
4  interface PluginState {
5    'code-yank': { blocks: CodeBlock[] }
6  }
7}
8