GitHubActionsのjson型定義を書くのが面倒だったからTypeScriptで定義してみたら思ったよりも簡単に定義できた

GitHubActions.d.ts

/*
Copyright 2020 KisaragiEffective
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
type Support = "windows-latest" | "windows-2019" | "ubuntu-latest" | "ubuntu-18.04" | "ubuntu-16.04" | "macos-latest" | "macos-10.15" | "self-hosted"
type Action = keyof TriggerSpec

type Defaults = {
    defaults: {
        run: {}
    }
}
type GitHubActions = {
    name?: string
    on: Action | Action[] | TriggerSpec
    jobs: JobConfiguration[]
} & Partial<Envilonment> & Partial<Defaults> & Partial<Conditional>

type MapType<K, V> = {[key: K]: V}
type Envilonment = {env: {[key: string]: number | string}}
type Conditional = {
    if: string
}
type Timeout = {
    "timeout-minutes": number
}

type JobConfiguration = {
    name: string
    "runs-on": Support
    steps: Step[]
    needs?: string[]
    outputs?: {[key: string]: string}
    // 
    strategy?: {
        matrix: {
            os: Support[]
            [key: string]: any
            include?: {
                os: Support
                [key: string]: any
            }[]
            exclude?: {
                os: Support
                [key: string]: any
            }
        }
        "fail-fast"?: boolean
        "max-parallel"?: number
        "continue-on-error"?: boolean
    }
    container?: ({
        image: string
        ports: number[]
        volumes?: string[]
        options?: string
    } & Partial<Envilonment>) | string
    services: {
        [name: string]: {
            image: string
            ports: string[]
            volumes?: string[]
            options?: string
        } & Partial<Envilonment>
    }
} & Partial<Envilonment> & Partial<Defaults> & Partial<Conditional> & Partial<Timeout>

type Step = {
    name: string
    uses?: string
    with?: {[key: string]: (string | boolean | number)} & {entrypoint: string}
    run?: string
    "working-directory"?: string
    shell?: "bash" | "pwsh" | "python" | "sh" | "cmd" | "powershell"
    "continue-on-error"?: boolean
} & Partial<Envilonment> & Partial<Timeout>

type UniqueArray<T extends (string | number)> = Array<T>

type BranchTagSpec = Partial<{branches: string[]} | {"branches-ignore": string[]}> & Partial<{tags: string[]} | {"tags-ignore": string[]}>

type PathSpec = Partial<{paths: string[]} | {"paths-ignore": string[]}>

type TriggerSpec = {
    check_run?: {
        types: UniqueArray<"created" | "rerequested" | "completed" | "requested_action">
    }

    check_suite?: {
        types: UniqueArray<"completed" | "requested" | "rerequested">
    }

    create?: {}

    delete?: {}

    deployment?: {}

    deployment_status?: {}

    fork?: {}

    // someone has just updated wiki
    gollum?: {}

    issue_comment?: {
        types: UniqueArray<"created" | "edited" | "deleted">
    }

    issues?: {
        types: UniqueArray<"opened" | "edited" | "deleted" | "transferred" | "pinned" | "unpinned" | "closed" | "reopened" | "assigned" | "unassigned" | "labeled" | "unlabeled" | "locked" | "unlocked" | "milestoned" | "demilestoned"> 
    }

    label?: {
        types: UniqueArray<"created" | "edited" | "deleted">
    }

    milestone?: {
        types: UniqueArray<"created" | "closed" | "opened" | "edited" | "deleted">
    }

    page_build?: {}

    project?: {
        types: UniqueArray<"created" | "updated" | "closed" | "reopened" | "edited" | "deleted">
    }

    project_card?: {
        types: UniqueArray<"created" | "moved" | "converted" | "edited" | "deleted">
    }

    project_column?: {
        types: UniqueArray<"created" | "updated" | "moved" | "deleted">
    }

    public?: {}

    pull_request?: {
        types: UniqueArray<"assigned" | "unassigned" | "labeled" | "unlabeled" | "opened" | "edited" | "closed" | "reopened" | "synchronize" | "ready_for_review" | "locked" | "unlocked" | "review_requested" | "review_request_removed">
    } & BranchTagSpec & PathSpec

    pull_request_review?: {
        types: UniqueArray<"submitted" | "edited" | "dismissed">
    }

    pull_request_review_comment?: {
        types: UniqueArray<"created" | "edited" | "deleted">
    }

    push?: BranchTagSpec & PathSpec

    registry_package?: {
        types: UniqueArray<"published" | "updated">
    }

    release?: {
        types: UniqueArray<"published" | "unpublished" | "created" | "edited" | "deleted" | "prereleased" | "released">
    }

    status?: {}

    watch?: {
        types: UniqueArray<"started">
    }

    schedule?: {
        cron: string
    }[]
}