[Harald Kirschner (digitarald)]

Fixes #343595.

Changes

• Accept string-valued command alongside bash/powershell in the Copilot CLI hook JSON schema, including completion metadata.
• Update the missing-command diagnostic and preserve the existing command-field alternatives.
• Add a regression test for the command property and accepted alternatives.

The reported version: 1 file already selects the CLI schema; its command-field requirement caused the squiggles. No harness-selection or runtime behavior changes are included.

The Local-format deprecation, default-snippet migration, and coordinated Configure Hooks changes are isolated in stacked draft #345634. This PR leaves the Local format and default snippet unchanged.

Validation

• The focused branch retains the original command fix (ed908b856cb) and merges updated main in 145578ff518; its diff against that main revision remains limited to the command schema and regression test.
• Standalone in-memory Ajv validation of the focused schema — passed 10 cases: command/bash/powershell, missing command, invalid command values, invalid type/timeout, Local compatibility, and the unchanged default snippet. A baseline regression check confirmed that the pre-fix schema rejects command-only input.
• git diff --check ed908b856cb^ ed908b856cb — passed.
• An independent full build/unit-test run of this focused branch was blocked during initial dependency bootstrap. After restoring public build dependencies, compilation, lint, hygiene, and 72 hook unit tests passed on stacked chat: deprecate the Local hook JSON format #345634, which includes this fix; those runs also include follow-up changes and are not an independent run of this branch.
• Live UI/CLI execution and broad type-checking were not run.

Manual Check

1. Open the JSON repro in Copilot CLI hook JSON validation rejects command-only hooks #343595 under .github/hooks/: command-only CLI hooks should have no missing-command diagnostic.
2. Remove the command or use a non-string value: validation should still reject the configuration.
3. Verify existing bash-only, powershell-only, and Local-format files remain accepted.

Draft for roblourens and Martin Aeschlimann (@aeschli).

[Copilot]

🟢 Approval recommended

The focused schema correction matches the reported requirement, preserves existing alternatives, and has regression coverage with no actionable defects identified.

No open issues 🎉

What changed in this PR

Fixes #343595 by allowing command in the Copilot CLI hook JSON schema, without changing harness selection or runtime behavior.

Changes:

• Accepts string-valued command alongside the existing bash and powershell alternatives.
• Adds completion metadata and updates the missing-command diagnostic.
• Adds a regression test for the command property and accepted alternatives.

File	Description
src/​vs/​workbench/​contrib/​chat/​test/​common/​promptSyntax/​hookSchema.test.ts	Tests the CLI schema’s command metadata and required-field alternatives.
src/​vs/​workbench/​contrib/​chat/​common/​promptSyntax/​hookSchema.ts	Accepts command and updates the validation diagnostic.

_{Review effort: Balanced}

[Martin Aeschlimann (aeschli)]

The command schema correction looks right. I recommend keeping this PR focused on #343595:

• Keep command in the CLI schema properties and required-field alternatives, together with the updated missing-command diagnostic.
• Move the Local-format deprecation and default-snippet migration into a separate follow-up PR.
• Add behavioral JSON-schema validation tests for command-only, bash-only, powershell-only, missing-command, and non-string-command cases; the added tests currently inspect schema structure rather than diagnostics.

The deprecation follow-up should coordinate Configure Hooks (which still creates Local-format files), the VS Code CLI event map (which omits preCompact and subagentStart), and input/output compatibility during migration. The runtime tags PascalCase hooks with _vsCodeCompat, which affects payload mapping, so renaming events is not necessarily behavior-preserving.

I verified with the built native runtime that both PascalCase and camelCase PreCompact/SubagentStart configurations load successfully. My earlier review concern that the runtime would drop those events was incorrect; the omission is in VS Code hook discovery/parsing, not runtime support.