Boolean inputs are not actually booleans

Describe the bug

Boolean type inputs do not work as expected; they are strings instead of booleans, even when surrounded by ${{ }} (e.g. in a step’s if condition).

To Reproduce Steps to reproduce the behavior:

Run this workflow using the workflow dispatch, with the foo input checkbox not ticked:

name: Thingy

on:
  workflow_dispatch:
    inputs:
      foo:
        description: Whether to foo
        type: boolean
        required: false
        default: false

jobs:
  thingy:
    runs-on: ubuntu-latest
    timeout-minutes: 5
    env:
      FOO: ${{ github.event.inputs.foo }}
    steps:
      - name: Check value
        run: |
          echo "The value is: $FOO"

      - name: Run if foo
        if: ${{ github.event.inputs.foo }}
        run: |
          echo "Foo!"

      - name: Don't run if foo  # Eh, I meant "Run if not foo"
        if: ${{ ! github.event.inputs.foo }}
        run: |
          echo "Foo!"

Expected behavior

When the input is false, the Run if foo step should be skipped , and the Don't run if foo step should run.

Runner Version and Platform

Version of your runner? 2.284.0

OS of the machine running the runner? ubuntu-latest (20.04.3)

What’s not working?

The value of github.event.inputs.foo is false, yet the Run if foo step runs and the Don't run if foo step is skipped.

Additional context

It is the same for a string input type or boolean input type (https://github.blog/changelog/2021-11-10-github-actions-input-types-for-manual-workflows/).

Only if: ${{ github.event.inputs.foo == 'true' }} works. So the input must be being treated as a string.

This goes against what the documentation says at https://docs.github.com/en/actions/learn-github-actions/expressions#about-expressions:

…evaluate an expression rather than treat it as a string.

${{ <expression> }}

[mike-carey]

Something that I also recently learned is that booleans are “strings” within workflow dispatches and composite actions but not reusable workflows.

For workflow_dispatch and composite action boolean inputs are actually strings:

if: inputs.my-boolean == 'true'

and

if: github.event.inputs.my-boolean == 'true'

will work.

However, for reusable workflows, the boolean is actually a boolean:

if: inputs.my-boolean == true

or

if: inputs.my-boolean

References

• Demo workflow using dispatch
• Demo composite action
• Demo reusable workflow
• Demo run

[ajaykn]

👋 We are working on some efforts in unifying the inputs context and will address these issues in future. So it should behave like inputs.boolean == true instead of strings (“true”) We will update once rolled out.