surshar / claude-code

Claude Code is an agentic coding tool that lives in your terminal, understands your codebase, and helps you code faster by executing routine tasks, explaining complex code, and handling git workflows - all through natural language commands.

Built by Anthropic · github.com/anthropics

diff: a shell command the tool held read-only fetches nothing, as the built-in panel's touch is gatedBrowse files

poteat authored on Sep 18, 2026 parent a92ea1c · commit c568a8cde3e2

6 changed files+74 -2compared with a92ea1c

Mmods/diff/hooks/register.ts

Mmods/diff/hooks/tools/index.ts

Amods/diff/hooks/tools/may-have-written.ts

Mmods/diff/tests/fixtures/index.ts

Amods/diff/tests/fixtures/read-only-answer.ts

Mmods/diff/tests/register.test.ts

Mmods/diff/hooks/register.ts+1 -2

		@@ -830,8 +830,7 @@
830	830	result.isError !== true
831	831
832	832	const isStale =
833		- isPaneOpen &&
834		- (isEdit ? hasEdited : result === undefined \|\| result.deny === undefined)
	833	+ isPaneOpen && (isEdit ? hasEdited : Tools.mayHaveWritten(result))
835	834
836	835	if (isStale) {
837	836	scheduleRefresh(engine)

Mmods/diff/hooks/tools/index.ts+1 -0

		@@ -1,4 +1,5 @@
1	1	export * from './editing-tools.js'
	2	+export * from './may-have-written.js'
2	3	export * from './shell-tools.js'
3	4	export * from './todo-tool.js'
4	5

Amods/diff/hooks/tools/may-have-written.ts+23 -0

		@@ -1,0 +1,23 @@
	1	+import type { ResultOf } from 'claude-code'
	2	+
	3	+/**
	4	+ * Whether a shell tool's outcome may have changed the working tree, as the
	5	+ * built-in gates its refresh: a throw or an answer, unless the engine says
	6	+ * the tool held the call read-only (`ls`, `git status`); never a deny.
	7	+ *
	8	+ * `isReadOnly` is read through a type that may lack it, ahead of the
	9	+ * declarations that name it; absent, the call counts as a write.
	10	+ *
	11	+ * @param result what `next` resolved to, or undefined when it threw
	12	+ * @returns true when a refresh is due
	13	+ */
	14	+export function mayHaveWritten(
	15	+ result: ResultOf['tool.call'] \| undefined,
	16	+): boolean {
	17	+ const settled: { deny?: string; isReadOnly?: boolean } \| undefined = result
	18	+
	19	+ return (
	20	+ settled === undefined \|\|
	21	+ (settled.deny === undefined && settled.isReadOnly !== true)
	22	+ )
	23	+}

Mmods/diff/tests/fixtures/index.ts+1 -0

		@@ -38,6 +38,7 @@
38	38	export * from './pane-view'
39	39	export * from './parse-file-diff'
40	40	export * from './poll-word.js'
	41	+export * from './read-only-answer.js'
41	42	export * from './renamed.js'
42	43	export * from './repository.js'
43	44	export * from './repository-of'

Amods/diff/tests/fixtures/read-only-answer.ts+13 -0

		@@ -1,0 +1,13 @@
	1	+import type { ResultOf } from 'claude-code'
	2	+
	3	+/**
	4	+ * A shell tool's answer as the engine gives it for a command the tool holds
	5	+ * read-only (`ls`, `git status`): the result, and `isReadOnly` beside it.
	6	+ *
	7	+ * Built through Object.assign, since the declarations may not name the
	8	+ * field yet; the plugin reads it through a type that may lack it too.
	9	+ */
	10	+export const READ_ONLY_ANSWER: ResultOf['tool.call'] = Object.assign(
	11	+ { result: 'listed' },
	12	+ { isReadOnly: true as const },
	13	+)

Mmods/diff/tests/register.test.ts+35 -0

		@@ -121,6 +121,41 @@
121	121	)
122	122	})
123	123
	124	+ test('a shell command the tool held read-only fetches nothing', async ($, on) => {
	125	+ const world = Fixtures.inRepository(on)
	126	+
	127	+ const fetchesSince = (read: number) =>
	128	+ world.runs.slice(read).filter(run => run.argv.includes('--numstat'))
	129	+ .length
	130	+
	131	+ on('tool.call', ($, e) =>
	132	+ e.tool === 'Bash' && e.command === 'ls'
	133	+ ? Fixtures.READ_ONLY_ANSWER
	134	+ : { result: 'done' },
	135	+ )
	136	+
	137	+ await $.session.start(Fixtures.SESSION)
	138	+ await $.command.run(Fixtures.DIFF)
	139	+ await world.clock.advance(Fixtures.SETTLE_MS)
	140	+
	141	+ const opened = world.runs.length
	142	+
	143	+ await $.tool.call({ tool: 'Bash', command: 'ls' })
	144	+ await world.clock.advance(Fixtures.SETTLE_MS)
	145	+
	146	+ expect(
	147	+ fetchesSince(opened),
	148	+ "read-only, the pane open: nothing, as the built-in's touch is gated",
	149	+ ).toBe(0)
	150	+
	151	+ const listed = world.runs.length
	152	+
	153	+ await $.tool.call({ tool: 'Bash', command: 'make' })
	154	+ await world.clock.advance(Fixtures.SETTLE_MS)
	155	+
	156	+ expect(fetchesSince(listed), 'a command that may write: one fetch').toBe(1)
	157	+ })
	158	+
124	159	test('/diff whose probe never answers probes once more', async ($, on) => {
125	160	const probes: (readonly string[])[] = []
126	161	const clock = Fixtures.startsSession(on)