Reader coverage.

Signed-off-by: Adam Rocska <adam.rocska@adams.solutions>

Sources/Api/Reader.swift

@@ -5,9 +5,7 @@ public class Reader<Model> where Model: DictionaryInitialisable {
 
   private let dbReader: DBReader.Reader
 
-  init(dbReader: DBReader.Reader) {
+  init(dbReader: DBReader.Reader) { self.dbReader = dbReader }
-    self.dbReader = dbReader
-  }
 
   func lookup(_ ip: IpAddress) -> Model? {
     guard let dictionary = dbReader.get(ip) else { return nil }

Tests/ApiTests/ReaderTest.swift

@@ -0,0 +1,78 @@
+import Foundation
+import XCTest
+@testable import struct MetadataReader.Metadata
+@testable import class Api.Reader
+import enum Decoder.Payload
+import enum IndexReader.IpAddress
+import protocol Api.DictionaryInitialisable
+import protocol DBReader.Reader
+
+fileprivate typealias ApiReader = Api.Reader
+fileprivate typealias DBReaderReader = DBReader.Reader
+
+class ReaderTest: XCTestCase {
+
+  func testLookup_returnsNilIfDbReaderLookupResolvedNil() {
+    let expectedIp: IpAddress = .v4("127.0.0.1")
+    var dbReaderLookupCalled  = false
+    let mockDBReader = MockDBReader { actualIp in
+      XCTAssertEqual(expectedIp, actualIp)
+      dbReaderLookupCalled = true
+      return nil
+    }
+    let reader = ApiReader<MockModel>(dbReader: mockDBReader)
+    XCTAssertNil(reader.lookup(expectedIp))
+    XCTAssertTrue(dbReaderLookupCalled)
+  }
+
+  func testLookup_returnsTheConstructedModelIfResolved() {
+    let expectedIp: IpAddress = .v4("127.0.0.1")
+    var dbReaderLookupCalled  = false
+    let stubDictionary        = [
+      "testString": Payload.utf8String("test"),
+      "testMap": Payload.map(["key": Payload.int32(123)])
+    ]
+    let mockDBReader = MockDBReader { actualIp in
+      XCTAssertEqual(expectedIp, actualIp)
+      dbReaderLookupCalled = true
+      return stubDictionary
+    }
+    let reader = ApiReader<MockModel>(dbReader: mockDBReader)
+    let model  = reader.lookup(expectedIp)
+    XCTAssertEqual(stubDictionary, model?.dictionary)
+  }
+
+}
+
+fileprivate class MockDBReader: DBReaderReader {
+  var metadata = Metadata(
+    nodeCount: 0,
+    recordSize: 0,
+    ipVersion: 0,
+    databaseType: "",
+    languages: [],
+    binaryFormatMajorVersion: 0,
+    binaryFormatMinorVersion: 0,
+    buildEpoch: 0,
+    description: [:],
+    metadataSectionSize: 0,
+    databaseSize: 0
+  )
+
+  private let mockGet: (IpAddress) -> [String: Payload]?
+
+  init(mockGet: @escaping (IpAddress) -> [String: Payload]?) {
+    self.mockGet = mockGet
+  }
+
+  func get(_ ip: IpAddress) -> [String: Payload]? { return mockGet(ip) }
+
+}
+
+struct MockModel: DictionaryInitialisable {
+
+  let dictionary: [String: Payload]?
+
+  init(_ dictionary: [String: Payload]?) { self.dictionary = dictionary }
+
+}