fix: the graph calculation with post_depends.

[boris-smidt-klarrio]

This bugfix fixes the graph calculation it seems that the 'post_depends' where incorrectly handled resulting in tasks where all dependending on eachother:

["task1"]
depends_post=[
    'task2',
    'task3',
    'task4',
]

["task2"]
run = "i'm task 2"

["task3"]
run = "i'm task 3"

["task4"]
run = "i'm task 4"

DEBUG Graph {
    Ty: "Directed",
    node_count: 3,
    edge_count: 6,
    edges: (2, 0), (1, 0), (1, 2), (2, 1), (0, 2), (0, 1),

[boris-smidt-klarrio]

It fixes:
#4398

[jdx]

looks identical to #4404

[boris-smidt-klarrio]

Not sure why this isn't correct?
If i understand the code correct a depends_post means that it adds an extra depends to the task it references in its depends_post.

I.e. the dependency is 'inversed'.

[boris-smidt-klarrio]

Oke so the issue is that this will result in

/home/boris/projects/mise/target/debug/mise task deps one two three
one
two
└── one
three
└── one

So when you run two and three, it would run one even tough it isn't in the running tasks.

So what we actually want is:

/home/boris/projects/mise/target/debug/mise task deps one
one
two
└── one
three
└── one

but when you have the dependencies of two you want to get:

/home/boris/projects/mise/target/debug/mise task deps two
two

So maybe we can correct this by looking at the post deps first, if there is a post_dependency
We need to resolve it at the end to see which 'tasks' with post_dependencies need to run to add the dependency?

[boris-smidt-klarrio]

I suspect the post_dependency is really a feature that increases the changes by a lot that you get 'cyclical' graphs.

Tracing the code:
https://github.com/klarrio-oss/mise/blob/e12b3469e3940e70cb550c66206c754ed7bd0772/src/task/deps.rs#L22-L22
https://github.com/klarrio-oss/mise/blob/e12b3469e3940e70cb550c66206c754ed7bd0772/src/cli/run.rs#L268-L268
https://github.com/klarrio-oss/mise/blob/e12b3469e3940e70cb550c66206c754ed7bd0772/src/cli/run.rs#L226-L226

The tasks vector we get to Deps::new is actually the tasks that have to run.
So in the code a list of tasks that needs to be run is created in all_tasks_to_run which is all tasks + depends.
So then the extra depends in created by adding post_depends to this list as a result of this change.

[boris-smidt-klarrio]

I've added an e2e test:
https://github.com/klarrio-oss/mise/blob/4daaf77c782296b5b224fc9434cb3d8e5173dbed/e2e/tasks/test_task_depends_post_inf_loop#L17-L17

[boris-smidt-klarrio]

I've run the deps command locally and that one is still incorrect:

mise task deps one
# one

mise task deps two
# two

mise task deps one two
# one
# two
# └── one

So i suppose the deps needs to be updated that it shows

mise task deps one
# one
# two
# └── one
# three
# └── one

[boris-smidt-klarrio]

@jdx Is there any way we can move this forward, it fixes the post_depends lockup bug.

[boris-smidt-klarrio]

I hope you can find some time to have another look at this to atleast have a better working post_dependency instead of a 'fully broken' version of it.