Task doesn't expand correctly YAML anchors in `for: matrix`

[marco-m-pix4d]

Description

Consider the following Taskfile:

version: '3'

dev_ws: &dev_ws
  - dev-user-1
  - dev-user-2

tasks:
  foo:
    cmds:
      - for:
          matrix:
            ENV:
              - dev
              - prod
            WS: *dev_ws
        silent: true
        cmd: |
          echo +++ {{.ITEM.ENV}} {{.ITEM.WS}}

If I run it, I get:

$ task -t foo.yml foo
err:  matrix values must be an array or a reference
file: foo.yml:14:13
  12 |       - for:
  13 |           matrix:
> 14 |             ENV:
     |             ^
  15 |               - dev
  16 |               - prod

On the other hand, the input file is correct YAML. If I ask yq (https://github.com/mikefarah/yq) to expand the YAML anchor, I get:

$ yq 'explode(.)' < foo.yml
version: '3'
dev_ws:
  - dev-user-1
  - dev-user-2
tasks:
  foo:
    cmds:
      - for:
          matrix:
            ENV:
              - dev
              - prod
            WS:
              - dev-user-1
              - dev-user-2
        silent: true
        cmd: |
          echo +++ {{.ITEM.ENV}} {{.ITEM.WS}}

and the irony, if I pass the output of yq to the stdin of Task, I get what I expected:

$ yq 'explode(.)' < foo.yml | task -t - foo
+++ dev dev-user-1
+++ dev dev-user-2
+++ prod dev-user-1
+++ prod dev-user-2

Version

3.43.2

Operating system

macOS, Linux

Experiments Enabled

None.

Example Taskfile

version: '3'

dev_ws: &dev_ws
  - dev-user-1
  - dev-user-2

tasks:
  foo:
    cmds:
      - for:
          matrix:
            ENV:
              - dev
              - prod
            WS: *dev_ws
        silent: true
        cmd: |
          echo +++ {{.ITEM.ENV}} {{.ITEM.WS}}

Thank you for Task! :-)

[andreynering]

Hi @marco-m-pix4d,

We do not support YAML anchors. The Go YAML lib does not play well with it given the Taskfile schema is complex.

[marco-m-pix4d]

Hello @andreynering,

I know about the unmaintained status of the Go YAML lib, so I understand. What I was wondering is whether the following would make sense:

• The yq tool I used in the demo is using gopkg.in/yaml.v3, as Task. I noticed this from the same error messages.
• YAML anchors are part of the YAML "substrate" itself: they do not know about any YAML schema, and rightly so: they arrive before anything else.
• So, at least in theory, it should be possible for Task to have a "preprocessor" step, the first step ever when reading a Taskfile: expand all YAML anchors, exactly as yq does. Then, do all the other currently existing steps, that know about the Task YAML schema and characteristics.

What am I missing?