foo.yaml

#in:
---
spec:
  tasks:
    - name: a
      taskRef:
        params:
          - name: pathInRepo
            value: tasks/a.yaml

    - name: b
      taskRef:
        params:
          - name: pathInRepo
            value: tasks/b.yaml

    - name: c
      taskRef:
        params:
          - name: pathInRepo
            value: tasks/c.yaml

#out:
---
spec:
  tasks:
    - name: a
      taskRef:
        params:
          - name: url
            value: https://foo.bar/
          - name: revision
            value: baz
          - name: pathInRepo
            value: tasks/a.yaml

    - name: b
      taskRef:
        params:
          - name: url
            value: https://foo.bar/
          - name: revision
            value: baz
          - name: pathInRepo
            value: tasks/b.yaml

    - name: c
      taskRef:
        params:
          - name: url
            value: https://foo.bar/
          - name: revision
            value: baz
          - name: pathInRepo
            value: tasks/c.yaml