Boolean fields doesn't work properly in scaffolder templates after Start Over

Expected Behavior

Consider the following piece of scaffolder template:

spec:
  owner: dx-team
  type: website

  # these are the steps which are rendered in the frontend with the form input
  parameters:
    - title: Docker registry
      properties:
        setup_docker_registry:
          title: Setup Docker registry
          type: boolean
          default: false

If we do not select this checkbox (false state), and after creating the project from the template we press the “start over” button, then the checkbox will become active.

Expected Behavior: checkmark in false state

Current Behavior

In the picture above, you can see that setup_docker_registry URL param is set to false, but the checkbox is set to true.

Possible Solution

I think the problem is the wrong typecasting. All parameters from the URL are read as strings, and in this case the string must be converted to boolean.

Steps to Reproduce

1. Create template from the following manifest

apiVersion: scaffolder.backstage.io/v1beta3
kind: Template
metadata:
  name: react
  title: React project template
  description: Template from which you can create a frontend application
  tags:
    - frontend
    - template
spec:
  owner: dx-team
  type: website
  parameters:
    - title: Docker registry
      properties:
        setup_docker_registry:
          title: Setup Docker registry
          type: boolean
          default: false

1. Register this template in your backstage app
2. go to the page for creating a project from this template
3. Leave checkbox unchecked (false state)
4. start project creating
5. Press “Start Over” button

Context

This bug leads to bad UX when using project templates

Your Environment

$ /app/node_modules/.bin/backstage-cli info
OS:   Linux 4.18.0-305.7.1.el8_4.x86_64 - linux/x64
node: v16.13.2
yarn: 1.22.15
cli:  0.11.0 (installed)

Dependencies:
  @backstage/app-defaults                                  0.1.4
  @backstage/backend-common                                0.10.3
  @backstage/backend-tasks                                 0.1.3
  @backstage/catalog-client                                0.5.4
  @backstage/catalog-model                                 0.9.9
  @backstage/cli-common                                    0.1.6
  @backstage/cli                                           0.11.0
  @backstage/config-loader                                 0.9.2
  @backstage/config                                        0.1.12
  @backstage/core-app-api                                  0.4.0
  @backstage/core-components                               0.7.6, 0.8.4
  @backstage/core-plugin-api                               0.1.13, 0.2.2, 0.5.0
  @backstage/dev-utils                                     0.2.17
  @backstage/errors                                        0.1.5, 0.2.0
  @backstage/integration-react                             0.1.18
  @backstage/integration                                   0.7.1
  @backstage/plugin-api-docs                               0.6.22
  @backstage/plugin-app-backend                            0.3.21
  @backstage/plugin-auth-backend                           0.6.2
  @backstage/plugin-catalog-backend                        0.20.0
  @backstage/plugin-catalog-common                         0.1.0
  @backstage/plugin-catalog-import                         0.7.9
  @backstage/plugin-catalog-react                          0.6.11
  @backstage/plugin-catalog                                0.7.8
  @backstage/plugin-github-actions                         0.4.31
  @backstage/plugin-org                                    0.3.34
  @backstage/plugin-permission-common                      0.3.1
  @backstage/plugin-permission-node                        0.3.0
  @backstage/plugin-permission-react                       0.2.2
  @backstage/plugin-proxy-backend                          0.2.15
  @backstage/plugin-scaffolder-backend-module-cookiecutter 0.1.8
  @backstage/plugin-scaffolder-backend                     0.15.20
  @backstage/plugin-scaffolder-common                      0.1.2
  @backstage/plugin-scaffolder                             0.11.18
  @backstage/plugin-search-backend-node                    0.4.4
  @backstage/plugin-search-backend                         0.3.0
  @backstage/plugin-search                                 0.5.5
  @backstage/plugin-sentry                                 0.3.33
  @backstage/plugin-tech-radar                             0.5.2
  @backstage/plugin-techdocs-backend                       0.12.3
  @backstage/plugin-techdocs                               0.12.14
  @backstage/plugin-todo-backend                           0.1.18
  @backstage/plugin-todo                                   0.1.18
  @backstage/plugin-user-settings                          0.3.16
  @backstage/search-common                                 0.2.1
  @backstage/techdocs-common                               0.11.3
  @backstage/test-utils                                    0.2.2
  @backstage/theme                                         0.2.14
  @backstage/types                                         0.1.1
  @backstage/version-bridge                                0.1.1
Done in 1.10s.

• Browser Information: Chrome, Safari (last versions)

[snehaljos]

Hi, @benjdlambert am interested to contribute, can I?

[benjdlambert]

Yes, sorry just something I forgot to clean up!