refactor template generation to use common use case

Package.swift

@@ -6,7 +6,7 @@ let package = Package(
     name: "FigmaAssetsFetch",
     platforms: [.macOS(.v10_15)],
     products: [
-           .executable(name: "figma-assets-fetch", targets: ["FigmaAssetsFetch"])
+        .executable(name: "figma-assets-fetch", targets: ["FigmaAssetsFetch"]),
     ],
     dependencies: [
         .package(url: "https://github.com/stencilproject/Stencil", from: "0.13.1"),
@@ -18,10 +18,14 @@ let package = Package(
             dependencies: [
                 .product(name: "Stencil", package: "Stencil"),
                 .product(name: "ArgumentParser", package: "swift-argument-parser"),
-            ]),
+            ]
+        ),
         .testTarget(
             name: "FigmaAssetsFetchTests",
-            dependencies: ["FigmaAssetsFetch"]
+            dependencies: ["FigmaAssetsFetch"],
+            resources: [
+                .process("Resources"),
+            ]
         ),
     ]
 )

README.md

@@ -28,8 +28,8 @@ Example template:
         case {{ color.name.camelCased }}
     {% endfor %}
 
-        public var colorValue: UIColor {
-            switch color {
+        public var value: UIColor {
+            switch self {
             {% for color in colors %}
             case .{{ color.name.camelCased }}:
                 return UIColor(
@@ -42,20 +42,21 @@ Example template:
             }
         }
     }
+
+Save it to file with `*.stencil` extension.
 
 ### Commands reference
 To run the utility you need to pass several parameters, use `figma-assets-fetch help` for detail description of parameters, or refer to the examples below.
 
 #### `colors-code-gen` command
 This command is used for template-based code generation of colors obtained from Figma file.
-
-    figma-assets-fetch \
-        colors-code-gen \
-        --figma-token $FIGMA_TOKEN \ #Figma API token
-        --colors-node-url "https://www.figma.com/file/1z5n1txr0nz7qMVzcS3Oif/figma-assets-fetch-palette-example?node-id=1%3A3" \
-        --templates-directory "$TEMPLATES_DIR" \ #Path to directory with Stencil templates
-        --template-name Colors.swift.stencil \ #File name of the Stencil template to use
-        --output "$OUT_FILE_PATH" #Where to save generated file
+
+    figma-assets-fetch \ 
+        colors-code-gen \ 
+        --figma-token $FIGMA_TOKEN \ #Figma API token \ 
+        --colors-node-url "https://www.figma.com/file/1z5n1txr0nz7qMVzcS3Oif/figma-assets-fetch-palette-example?node-id=1%3A3" \ 
+        --template-path "/Users/michael/Documents/ColorsEnum.stencil" \
+        --output "/Users/michael/Documents/Colors.swift"
 
 #### `colors-xc-assets` command
 This command is used to generate `*.xcassets` file with colors from Figma.

Sources/FigmaAssetsFetch/Application/CommandLineArguments/Colors/ColorsCodeGen.swift

@@ -13,90 +13,48 @@ struct ColorsCodeGen: ParsableCommand {
     @OptionGroup
     var options: Options
 
-    @Option(
-        help: "Figma frame url that contains a collection of ellipses with colors."
-    )
-    var colorsNodeURL: String = ""
-
-    @Option(
-        help: "Template file name to render."
-    )
-    var templateName: String = ""
+    @OptionGroup
+    var colorsOptions: ColorsOptions
 
     @Option(
-        help: "Templates directory path."
+        help: "Path to Stencil template file to render. It should have `*.stencil` extension."
     )
-    var templatesDirectory: String = ""
+    var templatePath: String = ""
 
     func run() {
-        let figmaAPI: FigmaAPIType = FigmaAPI(token: options.figmaToken)
-        let figmaURLParser: FigmaURLParserType = FigmaURLParser()
+        let source = FigmaColorsSource(
+            colorsURLPath: colorsOptions.colorsNodeURL,
+            darkColorsURLPath: colorsOptions.darkColorsNodeURL,
+            figmaAPI: FigmaAPI(token: options.figmaToken)
+        )
 
-        guard let figmaFileId = try? figmaURLParser.extractFileId(from: colorsNodeURL),
-              let colorsNodeId = try? figmaURLParser.extractNodeId(from: colorsNodeURL)
-        else {
-            print("Incorrect Figma URL")
-            Darwin.exit(1)
-        }
+        let render = TemplateFileSystemRender(templatePath: templatePath)
+
+        let useCase = GetRemoteColorsUseCase(
+            source: source,
+            render: render,
+            output: options.output
+        )
 
-        let cancellable = figmaAPI.requestFile(with: figmaFileId, nodeId: colorsNodeId)
-            .tryMap(render(figmaNodes:))
+        let cancellable = useCase.run()
             .sink(
                 receiveCompletion: process(completion:),
-                receiveValue: save(result:)
+                receiveValue: { _ in }
             )
 
         // Infinitely run the main loop to wait for our request.
         RunLoop.main.run()
         withExtendedLifetime(cancellable) {}
     }
 
-    private func render(figmaNodes: FileNodesResponse) throws -> String {
-        let paletteExtractor = FigmaPaletteParser()
-        let paletteColors = try paletteExtractor.extract(figmaNodes: figmaNodes)
-            .sorted(by: { first, second in first.name.original < second.name.original })
-
-        let context = ["colors": paletteColors]
-        let environment = Environment(
-            loader: FileSystemLoader(
-                paths: [
-                    Path(templatesDirectory),
-                ]
-            )
-        )
-        let rendered = try environment.renderTemplate(
-            name: templateName,
-            context: context
-        )
-
-        return rendered
-    }
-
     private func process(completion: Subscribers.Completion<Error>) {
         switch completion {
         case let .failure(error):
             print(error)
             Darwin.exit(1)
         case .finished:
+            print("Done.")
             Darwin.exit(0)
         }
     }
-
-    private func save(result: String) {
-        guard let output = URL(string: "file://\(options.output)") else {
-            print(result)
-            Darwin.exit(0)
-        }
-
-        do {
-            try result.write(
-                to: output,
-                atomically: true,
-                encoding: String.Encoding.utf8
-            )
-        } catch {
-            print(error)
-            Darwin.exit(1)
-        }
-    }
 }

Sources/FigmaAssetsFetch/Data/FileSystem/FileWriter.swift

@@ -18,12 +18,14 @@ public struct FileWriter: FileWriterType {
 
 public class FileWriterMock {
     public var paths: [String] = []
+    public var contents: [String?] = []
 
     public init() {}
 }
 
 extension FileWriterMock: FileWriterType {
     public func write(content: String?, at url: URL) throws {
         paths.append(url.path)
+        contents.append(content)
     }
 }

Sources/FigmaAssetsFetch/Data/Templates/TemplateFileSystemRender.swift

@@ -0,0 +1,52 @@
+import Foundation
+import PathKit
+import Stencil
+
+public enum TemplateFileSystemRenderError: Error {
+    case invalidTemplatePath
+    case invalidOutputPath
+}
+
+public struct TemplateFileSystemRender {
+    private let templatePath: String
+    private let fileWriter: FileWriterType
+
+    public init(
+        templatePath: String,
+        fileWriter: FileWriterType = FileWriter()
+    ) {
+        self.templatePath = templatePath
+        self.fileWriter = fileWriter
+    }
+}
+
+extension TemplateFileSystemRender: ColorsRender {
+    public func render(colors: [NamedColor], output: String) throws {
+        guard let templateURL = URL(string: "file://\(templatePath)"),
+              templateURL.lastPathComponent.contains(".stencil")
+        else {
+            throw TemplateFileSystemRenderError.invalidTemplatePath
+        }
+
+        guard let outputURL = URL(string: "file://\(output)") else {
+            throw TemplateFileSystemRenderError.invalidOutputPath
+        }
+
+        let context = ["colors": colors]
+
+        let environment = Environment(
+            loader: FileSystemLoader(
+                paths: [
+                    Path(templateURL.deletingLastPathComponent().path),
+                ]
+            )
+        )
+
+        let rendered = try environment.renderTemplate(
+            name: templateURL.lastPathComponent,
+            context: context
+        )
+
+        try fileWriter.write(content: rendered, at: outputURL)
+    }
+}

Tests/FigmaAssetsFetchTests/DataTests/Templates/TemplateFileSystemRenderTests.swift

@@ -0,0 +1,22 @@
+import XCTest
+
+@testable import FigmaAssetsFetch
+
+class TemplateFileSystemRenderTests: XCTestCase {
+    func testTemplateRendering() throws {
+        let mockFileWriter = FileWriterMock()
+        let render = TemplateFileSystemRender(
+            templatePath: Bundle.module.url(forResource: "TestTemplate", withExtension: "stencil")!.path,
+            fileWriter: mockFileWriter
+        )
+        let namedColor = NamedColor(
+            name: .init(name: "Bg / Primary"),
+            value: .init(r: 0.424, g: 0.459, b: 0.49, a: 1)
+        )
+
+        try render.render(colors: [namedColor], output: "/Test.swift")
+
+        assert(mockFileWriter.paths == ["/Test.swift"])
+        assert(mockFileWriter.contents == ["\nbgPrimary 0.424 0.459 0.49 1.0 6C757D\n\n"])
+    }
+}

Tests/FigmaAssetsFetchTests/DomainTests/UseCases/GetRemoteColorsUseCaseTests.swift

@@ -71,4 +71,56 @@ class GetRemoteColorsUseCaseTests: XCTestCase {
             "/Test.xcassets/bg_secondary.colorset/Contents.json",
         ].sorted())
     }
+
+    func testGetColorsAndRenderToStencilTemplate() throws {
+        let figmaAPIMock = FigmaAPIMock(mockedJSON: FigmaJSON.examplePalleteWithStyles)
+        let colorsSource = FigmaColorsSource(
+            colorsURLPath: "https://www.figma.com/file/1z5n1txr0nz7qMVzcS3Oif/figma-assets-fetch-palette-example?node-id=1%3A3",
+            figmaAPI: figmaAPIMock
+        )
+
+        let mockFileWriter = FileWriterMock()
+        let render = TemplateFileSystemRender(
+            templatePath: Bundle.module.url(forResource: "TestTemplate", withExtension: "stencil")!.path,
+            fileWriter: mockFileWriter
+        )
+
+        let useCase = GetRemoteColorsUseCase(
+            source: colorsSource,
+            render: render,
+            output: "/Test.swift"
+        )
+
+        var error: Error?
+        let expectation = self.expectation(description: "Figma colors source mock")
+
+        useCase.run()
+            .sink(
+                receiveCompletion: { completion in
+                    switch completion {
+                    case .finished:
+                        break
+                    case let .failure(encounteredError):
+                        error = encounteredError
+                    }
+
+                    expectation.fulfill()
+                },
+                receiveValue: { _ in }
+            )
+            .store(in: &cancellables)
+
+        waitForExpectations(timeout: 10)
+
+        XCTAssertNil(error)
+
+        assert(mockFileWriter.paths == ["/Test.swift"])
+        assert(
+            mockFileWriter
+                .contents ==
+                [
+                    "\nbgPrimary 0.0 0.48235294222831726 1.0 1.0 007BFF\n\nbgSuccess 0.1568627506494522 0.6549019813537598 0.2705882489681244 1.0 28A745\n\nbgDanger 0.8627451062202454 0.2078431397676468 0.2705882489681244 1.0 DC3545\n\nbgInfo 0.09019608050584793 0.6352941393852234 0.7215686440467834 1.0 17A2B8\n\nbgSecondary 0.42352941632270813 0.4588235318660736 0.4901960790157318 1.0 6C757D\n\n",
+                ]
+        )
+    }
 }

Tests/FigmaAssetsFetchTests/Resources/TestTemplate.stencil

@@ -0,0 +1,3 @@
+{% for color in colors %}
+{{ color.name.camelCased }} {{ color.value.r }} {{ color.value.g }} {{ color.value.b }} {{ color.value.a }} {{ color.value.hexValue }}
+{% endfor %}