Feature request : add a "fail fast" configuration entry

[Lucas-C]

Here is my use case:

• I have integration tests (in Java + with protractor) that are costly to execute (in term of execution time)
• when earlier hooks detect issues with the code (e.g. eslint checks), I don't want to execute my integration tests until I've fixed those errors

Btw, I don't ask to change the current behaviour, but could you develop on the reasons behind the design decision to run all tests, indifferently of their outcome ? What are the benefits ?

[asottile]

The main benefit to running all of the hooks is for fixers. That said, this seems like a reasonable idea. The unfortunate bit is there isn't a good place to put it in .pre-commit-config.yaml without breaking the schema :S

[Lucas-C]

Agreed.
I can't find the relevant issue but I remember seeing a plan to get rid of the JSON schemas : is that still considered ? And then, should this be pending on json schema removal ?
Alternatively we could maybe simply extend the schema to allow this optional new field.
It won't "break" anything in the sense that it will still be backward compatible.

[asottile]

Oh I imagined we would want a top level all-or-nothing option instead of having to repeat it in every hook. The breaking change I was thinking of was changing the config to be a map instead of a list (Which would enable a bunch of other things I've wanted to do). Apis are hard.

And yeah I'm planning on ditching JSON schema. if we're just adding a property to hooks it's probably not breaking (we've done it in the past)

[Lucas-C]

Ok, I imagined on my part that we could have something like this:

- config:
  - fail-fast: false
- repo: local
  hooks:
  - id: do_not_commit
    name: Block if "DO NOT COMMIT" is found
    entry: DO NOT COMMIT
    language: pcre
    files: ''
- config:
  - timeout: 120s
  - fail-fast: true

(The repetition of the same config property is just here to show a possible edge case, and because I lack imagination :D)

[asottile]

I'd rather have a format that looks like this, though migration will be somewhat difficult:

fail-fast: true
repos:
-   repo: local
    hooks:
    -   id: ...
        ...

[asottile]

This will be available in 1.1.0 (once released) -- I plan to also throw in a couple other things as well into this release.

The format for failing fast is:

fail_fast: true
repos:
- ...

as such it is only available with the v2 configuration introduced in 1.0.0

[Lucas-C]

Awesome, thanks !

[asottile]

This is now available in v1.1.0! Thanks again for the issue!