Add CI config lint resolver

Refactors to use string as content type

* Refactors mutation to use STRING_TYPE rather than ApolloUpload, since
the mutation cannot work with a path from the frontend
* Removes YamlProcessorResult type and returns StageType instead
* Adds status field to mutation to mirror implementation
* Makes comprehensive specs

Adds a changelog

Filters out jobless stages

Refactored to use custom types

* Added a ci_config type for stages, groups, jobs, needs
* Adds a new gitlab-ci.yml stub that has some includes
* Updates specs
* Updates docs and schema

Updates mutation to be a resolver instead

* Due to some changes, this was better fitted to be resolved in its own
resolver instead of being a mutation. Specs were changed and slightly
modified to reflect this.
* Adds type specs
* Adds some missing fields (size)
* Updates docs and schema
* Updates the changelog

app/graphql/resolvers/ci/config_resolver.rb

+# frozen_string_literal: true
+
+module Resolvers
+  module Ci
+    class ConfigResolver < BaseResolver
+      type Types::Ci::Config::ConfigType, null: true
+
+      argument :content, GraphQL::STRING_TYPE,
+               required: true,
+               description: 'Contents of .gitlab-ci.yml'
+
+      argument :include_merged_yaml, GraphQL::BOOLEAN_TYPE,
+                required: false,
+                description: 'Whether or not to include merged CI yaml in the response'
+
+      def resolve(content:, include_merged_yaml: false)
+        result = Gitlab::Ci::YamlProcessor.new(content).execute
+
+        if result.errors.empty?
+          stages = stages(result.stages)
+          jobs = jobs(result.jobs)
+          groups = groups(jobs)
+          stages = stage_groups(stages, groups)
+
+          response = {
+                        status: 'valid',
+                        errors: [],
+                        stages: stages.select { |stage| !stage[:groups].empty? }
+                     }
+        else
+          response = {
+                        status: 'invalid',
+                        errors: [result.errors.first]
+                     }
+        end
+
+        response.tap do |response|
+          response[:merged_yaml] = result.merged_yaml if include_merged_yaml
+        end
+      end
+
+      private
+
+      def stages(config_stages)
+        config_stages.map { |stage| { name: stage, groups: [] } }
+      end
+
+      def jobs(config_jobs)
+        config_jobs.map do |job_name, job|
+          {
+            name: job_name,
+            stage: job[:stage],
+            group_name: CommitStatus.new(name: job_name).group_name,
+            needs: needs(job) || []
+          }
+        end
+      end
+
+      def needs(job)
+        job.dig(:needs, :job)&.map do |job_need|
+          { name: job_need[:name], artifacts: job_need[:artifacts] }
+        end
+      end
+
+      def groups(jobs)
+        group_names = jobs.map { |job| job[:group_name] }.uniq
+        group_names.map do |group|
+          group_jobs = jobs.select { |job| job[:group_name] == group }
+          { jobs: group_jobs, name: group, stage: group_jobs.first[:stage], size: group_jobs.count }
+        end
+      end
+
+      def stage_groups(stage_data, groups)
+        stage_data.each do |stage|
+          stage[:groups] = groups.select { |group| group[:stage] == stage[:name] }
+        end
+      end
+    end
+  end
+end

app/graphql/types/ci/config/config_type.rb

+# frozen_string_literal: true
+
+module Types
+  module Ci
+    # rubocop: disable Graphql/AuthorizeTypes
+    module Config
+      class ConfigType < BaseObject
+        graphql_name 'CiConfig'
+
+        field :errors, GraphQL::STRING_TYPE, null: true,
+              description: 'Linting errors'
+        field :merged_yaml, GraphQL::STRING_TYPE, null: true,
+              description: 'Merged CI config YAML'
+        field :stages, [Types::Ci::Config::StageType], null: true,
+              description: 'Stages of the pipeline'
+        field :status, Types::Ci::Config::StatusEnum, null: true,
+              description: 'Status of linting, can be either valid or invalid'
+      end
+    end
+  end
+end

app/graphql/types/ci/config/group_type.rb

+# frozen_string_literal: true
+
+module Types
+  module Ci
+    # rubocop: disable Graphql/AuthorizeTypes
+    module Config
+      class GroupType < BaseObject
+        graphql_name 'CiConfigGroup'
+
+        field :name, GraphQL::STRING_TYPE, null: true,
+              description: 'Name of the job group'
+        field :jobs, [Types::Ci::Config::JobType], null: true,
+              description: 'Jobs in group'
+        field :size, GraphQL::INT_TYPE, null: true,
+              description: 'Size of the job group'
+      end
+    end
+  end
+end

app/graphql/types/ci/config/job_type.rb

+# frozen_string_literal: true
+
+module Types
+  module Ci
+    # rubocop: disable Graphql/AuthorizeTypes
+    module Config
+      class JobType < BaseObject
+        graphql_name 'CiConfigJob'
+
+        field :name, GraphQL::STRING_TYPE, null: true,
+              description: 'Name of the job'
+        field :needs, [Types::Ci::Config::NeedType], null: true,
+              description: 'Builds that must complete before the jobs run'
+      end
+    end
+  end
+end

app/graphql/types/ci/config/need_type.rb

+# frozen_string_literal: true
+
+module Types
+  module Ci
+    # rubocop: disable Graphql/AuthorizeTypes
+    module Config
+      class NeedType < BaseObject
+        graphql_name 'CiConfigNeed'
+
+        field :name, GraphQL::STRING_TYPE, null: true,
+              description: 'Name of the job'
+      end
+    end
+  end
+end

app/graphql/types/ci/config/stage_type.rb

+# frozen_string_literal: true
+
+module Types
+  module Ci
+    # rubocop: disable Graphql/AuthorizeTypes
+    module Config
+      class StageType < BaseObject
+        graphql_name 'CiConfigStage'
+
+        field :name, GraphQL::STRING_TYPE, null: true,
+              description: 'Name of the stage'
+        field :groups, [Types::Ci::Config::GroupType], null: true,
+              description: 'Groups of jobs for the stage'
+      end
+    end
+  end
+end

app/graphql/types/ci/config/status_enum.rb

+# frozen_string_literal: true
+
+module Types
+  module Ci
+    module Config
+      class StatusEnum < BaseEnum
+        graphql_name 'CiConfigStatus'
+        description 'Values for YAML processor result'
+
+        value 'VALID', 'Valid `gitlab-ci.yml`'
+        value 'INVALID', 'Invalid `gitlab-ci.yml`'
+      end
+    end
+  end
+end

app/graphql/types/query_type.rb

@@ -91,6 +91,10 @@ module Types
       description: 'Get runner setup instructions',
       resolver: Resolvers::Ci::RunnerSetupResolver
 
+    field :ci_config, Types::Ci::Config::ConfigType, null: true,
+          description: 'Contents of gitlab-ci.yml file',
+          resolver: Resolvers::Ci::ConfigResolver
+
     def design_management
       DesignManagementObject.new(nil)
     end

changelogs/unreleased/lm-add-ci-config-0.yml

+---
+title: 'GraphQL: Adds ciConfig field and corresponding response fields'
+merge_request: 46912
+author:
+type: added

doc/api/graphql/reference/gitlab_schema.graphql

@@ -2237,6 +2237,91 @@ type BurnupChartDailyTotals {
   scopeWeight: Int!
 }
 
+type CiConfig {
+  """
+  Linting errors
+  """
+  errors: String
+
+  """
+  Merged CI config YAML
+  """
+  mergedYaml: String
+
+  """
+  Stages of the pipeline
+  """
+  stages: [CiConfigStage!]
+
+  """
+  Status of linting, can be either valid or invalid
+  """
+  status: CiConfigStatus
+}
+
+type CiConfigGroup {
+  """
+  Jobs in group
+  """
+  jobs: [CiConfigJob!]
+
+  """
+  Name of the job group
+  """
+  name: String
+
+  """
+  Size of the job group
+  """
+  size: Int
+}
+
+type CiConfigJob {
+  """
+  Name of the job
+  """
+  name: String
+
+  """
+  Builds that must complete before the jobs run
+  """
+  needs: [CiConfigNeed!]
+}
+
+type CiConfigNeed {
+  """
+  Name of the job
+  """
+  name: String
+}
+
+type CiConfigStage {
+  """
+  Groups of jobs for the stage
+  """
+  groups: [CiConfigGroup!]
+
+  """
+  Name of the stage
+  """
+  name: String
+}
+
+"""
+Values for YAML processor result
+"""
+enum CiConfigStatus {
+  """
+  Invalid `gitlab-ci.yml`
+  """
+  INVALID
+
+  """
+  Valid `gitlab-ci.yml`
+  """
+  VALID
+}
+
 type CiGroup {
   """
   Detailed status of the group
@@ -17849,6 +17934,21 @@ type PromoteToEpicPayload {
 }
 
 type Query {
+  """
+  Contents of gitlab-ci.yml file
+  """
+  ciConfig(
+    """
+    Contents of .gitlab-ci.yml
+    """
+    content: String!
+
+    """
+    Whether or not to include merged CI yaml in the response
+    """
+    includeMergedYaml: Boolean
+  ): CiConfig
+
   """
   Find a container repository
   """

doc/api/graphql/reference/gitlab_schema.json

@@ -6000,6 +6000,294 @@
           "enumValues": null,
           "possibleTypes": null
         },
+        {
+          "kind": "OBJECT",
+          "name": "CiConfig",
+          "description": null,
+          "fields": [
+            {
+              "name": "errors",
+              "description": "Linting errors",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "mergedYaml",
+              "description": "Merged CI config YAML",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "stages",
+              "description": "Stages of the pipeline",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "LIST",
+                "name": null,
+                "ofType": {
+                  "kind": "NON_NULL",
+                  "name": null,
+                  "ofType": {
+                    "kind": "OBJECT",
+                    "name": "CiConfigStage",
+                    "ofType": null
+                  }
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "status",
+              "description": "Status of linting, can be either valid or invalid",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "ENUM",
+                "name": "CiConfigStatus",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
+        {
+          "kind": "OBJECT",
+          "name": "CiConfigGroup",
+          "description": null,
+          "fields": [
+            {
+              "name": "jobs",
+              "description": "Jobs in group",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "LIST",
+                "name": null,
+                "ofType": {
+                  "kind": "NON_NULL",
+                  "name": null,
+                  "ofType": {
+                    "kind": "OBJECT",
+                    "name": "CiConfigJob",
+                    "ofType": null
+                  }
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "name",
+              "description": "Name of the job group",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "size",
+              "description": "Size of the job group",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "SCALAR",
+                "name": "Int",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
+        {
+          "kind": "OBJECT",
+          "name": "CiConfigJob",
+          "description": null,
+          "fields": [
+            {
+              "name": "name",
+              "description": "Name of the job",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "needs",
+              "description": "Builds that must complete before the jobs run",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "LIST",
+                "name": null,
+                "ofType": {
+                  "kind": "NON_NULL",
+                  "name": null,
+                  "ofType": {
+                    "kind": "OBJECT",
+                    "name": "CiConfigNeed",
+                    "ofType": null
+                  }
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
+        {
+          "kind": "OBJECT",
+          "name": "CiConfigNeed",
+          "description": null,
+          "fields": [
+            {
+              "name": "name",
+              "description": "Name of the job",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
+        {
+          "kind": "OBJECT",
+          "name": "CiConfigStage",
+          "description": null,
+          "fields": [
+            {
+              "name": "groups",
+              "description": "Groups of jobs for the stage",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "LIST",
+                "name": null,
+                "ofType": {
+                  "kind": "NON_NULL",
+                  "name": null,
+                  "ofType": {
+                    "kind": "OBJECT",
+                    "name": "CiConfigGroup",
+                    "ofType": null
+                  }
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "name",
+              "description": "Name of the stage",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
+        {
+          "kind": "ENUM",
+          "name": "CiConfigStatus",
+          "description": "Values for YAML processor result",
+          "fields": null,
+          "inputFields": null,
+          "interfaces": null,
+          "enumValues": [
+            {
+              "name": "VALID",
+              "description": "Valid `gitlab-ci.yml`",
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "INVALID",
+              "description": "Invalid `gitlab-ci.yml`",
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "possibleTypes": null
+        },
         {
           "kind": "OBJECT",
           "name": "CiGroup",
@@ -52141,6 +52429,43 @@
           "name": "Query",
           "description": null,
           "fields": [
+            {
+              "name": "ciConfig",
+              "description": "Contents of gitlab-ci.yml file",
+              "args": [
+                {
+                  "name": "content",
+                  "description": "Contents of .gitlab-ci.yml",
+                  "type": {
+                    "kind": "NON_NULL",
+                    "name": null,
+                    "ofType": {
+                      "kind": "SCALAR",
+                      "name": "String",
+                      "ofType": null
+                    }
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "includeMergedYaml",
+                  "description": "Whether or not to include merged CI yaml in the response",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "Boolean",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                }
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "CiConfig",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
             {
               "name": "containerRepository",
               "description": "Find a container repository",

doc/api/graphql/reference/index.md

@@ -367,6 +367,43 @@ Represents the total number of issues and their weights for a particular day.
 | `scopeCount` | Int! | Number of issues as of this day |
 | `scopeWeight` | Int! | Total weight of issues as of this day |
 
+### CiConfig
+
+| Field | Type | Description |
+| ----- | ---- | ----------- |
+| `errors` | String | Linting errors |
+| `mergedYaml` | String | Merged CI config YAML |
+| `stages` | CiConfigStage! => Array | Stages of the pipeline |
+| `status` | CiConfigStatus | Status of linting, can be either valid or invalid |
+
+### CiConfigGroup
+
+| Field | Type | Description |
+| ----- | ---- | ----------- |
+| `jobs` | CiConfigJob! => Array | Jobs in group |
+| `name` | String | Name of the job group |
+| `size` | Int | Size of the job group |
+
+### CiConfigJob
+
+| Field | Type | Description |
+| ----- | ---- | ----------- |
+| `name` | String | Name of the job |
+| `needs` | CiConfigNeed! => Array | Builds that must complete before the jobs run |
+
+### CiConfigNeed
+
+| Field | Type | Description |
+| ----- | ---- | ----------- |
+| `name` | String | Name of the job |
+
+### CiConfigStage
+
+| Field | Type | Description |
+| ----- | ---- | ----------- |
+| `groups` | CiConfigGroup! => Array | Groups of jobs for the stage |
+| `name` | String | Name of the stage |
+
 ### CiGroup
 
 | Field | Type | Description |
@@ -3915,6 +3952,15 @@ Types of blob viewers.
 | `rich` |  |
 | `simple` |  |
 
+### CiConfigStatus
+
+Values for YAML processor result.
+
+| Value | Description |
+| ----- | ----------- |
+| `INVALID` | Invalid `gitlab-ci.yml` |
+| `VALID` | Valid `gitlab-ci.yml` |
+
 ### CommitActionMode
 
 Mode of a commit action.

spec/graphql/resolvers/ci/config_resolver_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Resolvers::Ci::ConfigResolver do
+  include GraphqlHelpers
+
+  describe '#resolve' do
+    context 'with a valid .gitlab-ci.yml' do
+      let_it_be(:content) do
+        File.read(Rails.root.join('spec/support/gitlab_stubs/gitlab_ci_includes.yml'))
+      end
+
+      it 'lints the ci config file' do
+        response = resolve(described_class, args: { content: content, include_merged_yaml: false }, ctx: {})
+
+        expect(response[:status]).to eq('valid')
+        expect(response[:errors]).to be_empty
+      end
+
+      it 'returns the correct structure' do
+        response = resolve(described_class, args: { content: content, include_merged_yaml: false }, ctx: {})
+
+        response_groups = response[:stages].map { |stage| stage[:groups] }.flatten
+        response_jobs = response.dig(:stages, 0, :groups, 0, :jobs)
+        response_needs = response.dig(:stages, -1, :groups, 0, :jobs, 0, :needs)
+
+        expect(response[:stages]).to include(
+          hash_including(name: 'build'), hash_including(name: 'test')
+        )
+        expect(response_groups).to include(
+          hash_including(name: 'rspec', size: 2),
+          hash_including(name: 'spinach', size: 1),
+          hash_including(name: 'docker', size: 1)
+        )
+
+        expect(response_jobs).to include(
+          hash_including(group_name: 'rspec', name: :'rspec 0 1', needs: [], stage: 'build'),
+          hash_including(group_name: 'rspec', name: :'rspec 0 2', needs: [], stage: 'build')
+        )
+        expect(response_needs).to include(
+          hash_including(name: 'rspec 0 1'), hash_including(name: 'spinach')
+        )
+      end
+    end
+
+    context 'with an invalid .gitlab-ci.yml' do
+      it 'responds with errors about invalid syntax' do
+        response = resolve(described_class, args: { content: 'invalid', include_merged_yaml: false }, ctx: {})
+
+        expect(response[:status]).to eq('invalid')
+        expect(response[:errors]).to eq(['Invalid configuration format'])
+      end
+    end
+  end
+end

spec/graphql/types/ci/config/config_type_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Types::Ci::Config::ConfigType do
+  specify { expect(described_class.graphql_name).to eq('CiConfig') }
+
+  it 'exposes the expected fields' do
+    expected_fields = %i[
+      errors
+      mergedYaml
+      stages
+      status
+    ]
+
+    expect(described_class).to have_graphql_fields(*expected_fields)
+  end
+end

spec/graphql/types/ci/config/group_type_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Types::Ci::Config::GroupType do
+  specify { expect(described_class.graphql_name).to eq('CiConfigGroup') }
+
+  it 'exposes the expected fields' do
+    expected_fields = %i[
+      name
+      jobs
+      size
+    ]
+
+    expect(described_class).to have_graphql_fields(*expected_fields)
+  end
+end

spec/graphql/types/ci/config/job_type_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Types::Ci::Config::JobType do
+  specify { expect(described_class.graphql_name).to eq('CiConfigJob') }
+
+  it 'exposes the expected fields' do
+    expected_fields = %i[
+      name
+      needs
+    ]
+
+    expect(described_class).to have_graphql_fields(*expected_fields)
+  end
+end

spec/graphql/types/ci/config/need_type_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Types::Ci::Config::NeedType do
+  specify { expect(described_class.graphql_name).to eq('CiConfigNeed') }
+
+  it 'exposes the expected fields' do
+    expected_fields = %i[
+      name
+    ]
+
+    expect(described_class).to have_graphql_fields(*expected_fields)
+  end
+end

spec/graphql/types/ci/config/stage_type_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Types::Ci::Config::StageType do
+  specify { expect(described_class.graphql_name).to eq('CiConfigStage') }
+
+  it 'exposes the expected fields' do
+    expected_fields = %i[
+      name
+      groups
+    ]
+
+    expect(described_class).to have_graphql_fields(*expected_fields)
+  end
+end

spec/support/gitlab_stubs/gitlab_ci_includes.yml

+rspec 0 1:
+  stage: build
+  script: "rake spec"
+  needs: []
+
+rspec 0 2:
+  stage: build
+  script: "rake spec"
+  needs: []
+
+spinach:
+  stage: build
+  script: "rake spinach"
+  needs: []
+
+docker:
+  stage: test
+  script: "curl http://dockerhub/URL"
+  needs: [spinach, rspec 0 1]