feat: OpenFeature provider for GO Feature Flag (#1)

.github/workflows/swift.yaml

@@ -21,11 +21,14 @@ jobs:
         run: swift build
       - name: Run tests
         run: swift test --enable-code-coverage
+      - name: Prepare Code Coverage
+        run: xcrun llvm-cov export -format="lcov" .build/debug/go-feature-flag-providerPackageTests.xctest/Contents/MacOS/go-feature-flag-providerPackageTests  -instr-profile .build/debug/codecov/default.profdata > info.lcov
       - name: Upload coverage reports to Codecov
         uses: codecov/codecov-action@v4
         with:
           fail_ci_if_error: true
           token: ${{ secrets.CODECOV_TOKEN }}
+          files: info.lcov
         env:
           CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
   lint:

.swiftlint.yml

@@ -0,0 +1,75 @@
+# By default, SwiftLint uses a set of sensible default rules you can adjust:
+disabled_rules: # rule identifiers turned on by default to exclude from running
+  - colon
+  - comma
+  - control_statement
+opt_in_rules: # some rules are turned off by default, so you need to opt-in
+  - empty_count # find all the available rules by running: `swiftlint rules`
+
+# Alternatively, specify all rules explicitly by uncommenting this option:
+# only_rules: # delete `disabled_rules` & `opt_in_rules` if using this
+#   - empty_parameters
+#   - vertical_whitespace
+
+analyzer_rules: # rules run by `swiftlint analyze`
+  - explicit_self
+
+# Case-sensitive paths to include during linting. Directory paths supplied on the
+# command line will be ignored.
+included: 
+  - Sources
+excluded: # case-sensitive paths to ignore during linting. Takes precedence over `included`
+  - Carthage
+  - Pods
+  - Sources/ExcludedFolder
+  - Sources/ExcludedFile.swift
+  - Sources/*/ExcludedFile.swift # exclude files with a wildcard
+
+# If true, SwiftLint will not fail if no lintable files are found.
+allow_zero_lintable_files: false
+
+# If true, SwiftLint will treat all warnings as errors.
+strict: false
+
+# The path to a baseline file, which will be used to filter out detected violations.
+baseline: Baseline.json
+
+# The path to save detected violations to as a new baseline.
+write_baseline: Baseline.json
+
+# configurable rules can be customized from this configuration file
+# binary rules can set their severity level
+force_cast: warning # implicitly
+force_try:
+  severity: warning # explicitly
+# rules that have both warning and error levels, can set just the warning level
+# implicitly
+line_length: 120
+# they can set both implicitly with an array
+type_body_length:
+  - 300 # warning
+  - 400 # error
+# or they can set both explicitly
+file_length:
+  warning: 500
+  error: 1200
+# naming rules can set warnings/errors for min_length and max_length
+# additionally they can set excluded names
+type_name:
+  min_length: 4 # only warning
+  max_length: # warning and error
+    warning: 40
+    error: 50
+  excluded: iPhone # excluded via string
+  allowed_symbols: ["_"] # these are allowed in type names
+identifier_name:
+  min_length: # only min_length
+    error: 4 # only error
+  excluded: # excluded via string array
+    - id
+    - URL
+    - url
+    - GlobalAPIKey
+    - key
+    - dto
+reporter: "xcode" # reporter type (xcode, json, csv, checkstyle, codeclimate, junit, html, emoji, sonarqube, markdown, github-actions-logging, summary)

Package.resolved

@@ -0,0 +1,16 @@
+{
+  "object": {
+    "pins": [
+      {
+        "package": "OpenFeature",
+        "repositoryURL": "https://github.com/open-feature/swift-sdk.git",
+        "state": {
+          "branch": null,
+          "revision": "02b033c954766e86d5706bfc8ee5248244c11e77",
+          "version": "0.1.0"
+        }
+      }
+    ]
+  },
+  "version": 1
+}

Package.swift

@@ -0,0 +1,35 @@
+// swift-tools-version: 5.5
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "go-feature-flag-provider",
+    platforms: [
+        .iOS(.v14),
+        .macOS(.v12)
+    ],
+    products: [
+        .library(
+            name: "go-feature-flag-provider",
+            targets: ["go-feature-flag-provider"])
+    ],
+    dependencies: [
+        .package(url: "https://github.com/open-feature/swift-sdk.git", from: "0.1.0")
+    ],
+    targets: [
+        .target(
+            name: "go-feature-flag-provider",
+            dependencies: [
+                .product(name: "OpenFeature", package: "swift-sdk")
+            ],
+            plugins:[]
+        ),
+        .testTarget(
+            name: "go-feature-flag-providerTests",
+            dependencies: [
+                "go-feature-flag-provider"
+            ]
+        )
+    ]
+)

Sources/go-feature-flag-provider/controller/ofrep_api.swift

@@ -0,0 +1,79 @@
+import Foundation
+import OpenFeature
+
+class OfrepAPI {
+    private let networkingService: NetworkingService
+    private var etag: String = ""
+    private let options: GoFeatureFlagProviderOptions
+
+    init(networkingService: NetworkingService, options: GoFeatureFlagProviderOptions) {
+        self.networkingService = networkingService
+        self.options = options
+    }
+
+    func postBulkEvaluateFlags(context: EvaluationContext?) async throws -> (OfrepEvaluationResponse, HTTPURLResponse) {
+        guard let context = context else {
+            throw OpenFeatureError.invalidContextError
+        }
+        try validateContext(context: context)
+
+        guard let url = URL(string: options.endpoint) else {
+            throw InvalidOptions.invalidEndpoint(message: "endpoint [" + options.endpoint + "] is not valid")
+        }
+        let ofrepURL = url.appendingPathComponent("ofrep/v1/evaluate/flags")
+        var request = URLRequest(url: ofrepURL)
+        request.httpMethod = "POST"
+        request.httpBody = try EvaluationRequest.convertEvaluationContext(context: context).asJSONData()
+        request.setValue(
+            "application/json",
+            forHTTPHeaderField: "Content-Type"
+        )
+
+        if etag != "" {
+            request.setValue(etag, forHTTPHeaderField: "If-None-Match")
+        }
+
+        let (data, response) = try await networkingService.doRequest(for: request)
+        guard let httpResponse = response as? HTTPURLResponse else {
+            throw OfrepError.httpResponseCastError
+        }
+
+        if httpResponse.statusCode == 401 {
+            throw OfrepError.apiUnauthorizedError(response: httpResponse)
+        }
+        if httpResponse.statusCode == 403 {
+            throw OfrepError.forbiddenError(response: httpResponse)
+        }
+        if httpResponse.statusCode == 429 {
+            throw OfrepError.apiTooManyRequestsError(response: httpResponse)
+        }
+        if httpResponse.statusCode > 400 {
+            throw OfrepError.unexpectedResponseError(response: httpResponse)
+        }
+        if httpResponse.statusCode == 304 {
+            return (OfrepEvaluationResponse(flags: [], errorCode: nil, errorDetails: nil), httpResponse)
+        }
+
+        // Store ETag to use it in the next request
+        if let etagHeaderValue = httpResponse.value(forHTTPHeaderField: "ETag") {
+            if etagHeaderValue != "" && httpResponse.statusCode == 200 {
+                etag = etagHeaderValue
+            }
+        }
+
+        do {
+            let dto = try JSONDecoder().decode(EvaluationResponseDTO.self, from: data)
+            let evaluationResponse = OfrepEvaluationResponse.fromEvaluationResponseDTO(dto: dto)
+            return (evaluationResponse, httpResponse)
+        } catch {
+            throw OfrepError.unmarshallError(error: error)
+        }
+    }
+
+    private func validateContext(context: EvaluationContext) throws {
+        let targetingKey = context.getTargetingKey()
+        if targetingKey.isEmpty {
+            throw OpenFeatureError.targetingKeyMissingError
+        }
+    }
+}

Sources/go-feature-flag-provider/exception/ofrep_exceptions.swift

@@ -0,0 +1,18 @@
+//
+//  File.swift
+//  
+//
+//  Created by thomas.poignant on 27/06/2024.
+//
+
+import Foundation
+
+enum OfrepError: Error {
+    case httpResponseCastError
+    case unmarshallError(error: Error)
+    case apiUnauthorizedError(response: HTTPURLResponse)
+    case forbiddenError(response: HTTPURLResponse)
+    case apiTooManyRequestsError(response: HTTPURLResponse)
+    case unexpectedResponseError(response: HTTPURLResponse)
+    case waitingRetryLater(date: Date?)
+}

Sources/go-feature-flag-provider/exception/option_exceptions.swift

@@ -0,0 +1,13 @@
+//
+//  File.swift
+//  
+//
+//  Created by thomas.poignant on 27/06/2024.
+//
+
+import Foundation
+
+enum InvalidOptions: Error {
+    case invalidEndpoint(message: String)
+
+}