diff --git a/Demo/BuildConfigSwiftDemo/Sources/Data/BaseEntities.swift b/Demo/BuildConfigSwiftDemo/Sources/Data/BaseEntities.swift
new file mode 100644
index 0000000..fbdb9ef
--- /dev/null
+++ b/Demo/BuildConfigSwiftDemo/Sources/Data/BaseEntities.swift
@@ -0,0 +1,15 @@
+//
+//  BaseEntities.swift
+//  BuildConfigSwiftDemo
+//
+//  Created by 417.72KI on 2023/10/05.
+//  Copyright © 2023 417.72KI. All rights reserved.
+//
+
+import Foundation
+
+protocol Request: Encodable, Hashable {
+}
+
+protocol Response: Decodable, Hashable {
+}
diff --git a/Demo/BuildConfigSwiftDemo/Sources/Data/LoginRequest.swift b/Demo/BuildConfigSwiftDemo/Sources/Data/LoginRequest.swift
new file mode 100644
index 0000000..c5cb40a
--- /dev/null
+++ b/Demo/BuildConfigSwiftDemo/Sources/Data/LoginRequest.swift
@@ -0,0 +1,14 @@
+//
+//  LoginRequest.swift
+//  BuildConfigSwiftDemo
+//
+//  Created by 417.72KI on 2023/10/05.
+//  Copyright © 2023 417.72KI. All rights reserved.
+//
+
+import Foundation
+
+struct LoginRequest: Request {
+    var id: String
+    var password: String
+}
diff --git a/Demo/BuildConfigSwiftDemo/Sources/Data/LoginResponse.swift b/Demo/BuildConfigSwiftDemo/Sources/Data/LoginResponse.swift
new file mode 100644
index 0000000..e675750
--- /dev/null
+++ b/Demo/BuildConfigSwiftDemo/Sources/Data/LoginResponse.swift
@@ -0,0 +1,14 @@
+//
+//  LoginResponse.swift
+//  BuildConfigSwiftDemo
+//
+//  Created by 417.72KI on 2023/10/05.
+//  Copyright © 2023 417.72KI. All rights reserved.
+//
+
+import Foundation
+
+struct LoginResponse: Response {
+    var accessToken: String
+    var refreshToken: String
+}
diff --git a/Demo/BuildConfigSwiftDemo/Sources/Data/SearchResponse.swift b/Demo/BuildConfigSwiftDemo/Sources/Data/SearchResponse.swift
new file mode 100644
index 0000000..6a3ccd7
--- /dev/null
+++ b/Demo/BuildConfigSwiftDemo/Sources/Data/SearchResponse.swift
@@ -0,0 +1,19 @@
+//
+//  SearchResponse.swift
+//  BuildConfigSwiftDemo
+//
+//  Created by 417.72KI on 2023/10/05.
+//  Copyright © 2023 417.72KI. All rights reserved.
+//
+
+import Foundation
+
+struct SearchResponse: Response {
+    var items: [Item]
+}
+
+extension SearchResponse {
+    struct Item: Response {
+        var name: String
+    }
+}
diff --git a/Demo/BuildConfigSwiftDemo/Sources/Repository/APIClient.swift b/Demo/BuildConfigSwiftDemo/Sources/Repository/APIClient.swift
new file mode 100644
index 0000000..f776370
--- /dev/null
+++ b/Demo/BuildConfigSwiftDemo/Sources/Repository/APIClient.swift
@@ -0,0 +1,61 @@
+//
+//  APIClient.swift
+//  BuildConfigSwiftDemo
+//
+//  Created by 417.72KI on 2023/10/05.
+//  Copyright © 2023 417.72KI. All rights reserved.
+//
+
+import Foundation
+
+struct APIClient {
+    var config: BuildConfig.Api
+    var session: URLSession
+}
+
+extension APIClient {
+    var host: URL { URL(string: "https://\(config.host)")! }
+
+    var decoder: JSONDecoder {
+        let decoder = JSONDecoder()
+        decoder.keyDecodingStrategy = .convertFromSnakeCase
+        return decoder
+    }
+
+    var encoder: JSONEncoder {
+        let encoder = JSONEncoder()
+        encoder.keyEncodingStrategy = .convertToSnakeCase
+        return encoder
+    }
+}
+
+extension APIClient {
+    func endpoint<E>(_ keyPath: KeyPath<BuildConfig.Api.Endpoint, E>) -> E {
+        config.endpoint[keyPath: keyPath]
+    }
+}
+
+extension APIClient {
+    func login(id: String, password: String) async throws -> LoginResponse {
+        let endpoint = endpoint(\.login)
+        let url = host.appendingPathComponent(endpoint.path)
+        var request = URLRequest(url: url)
+        request.httpMethod = endpoint.method
+        request.httpBody = try encoder.encode(LoginRequest(id: id, password: password))
+        let (data, _) = try await session.data(for: request)
+        return try decoder.decode(LoginResponse.self, from: data)
+    }
+
+    @available(iOS 16.0, *)
+    func search(_ text: String) async throws -> SearchResponse {
+        let endpoint = endpoint(\.search)
+        let url = host.appendingPathComponent(endpoint.path)
+            .appending(queryItems: [
+                URLQueryItem(name: "text", value: text)
+            ])
+        var request = URLRequest(url: url)
+        request.httpMethod = endpoint.method
+        let (data, _) = try await session.data(for: request)
+        return try decoder.decode(SearchResponse.self, from: data)
+    }
+}
diff --git a/Demo/BuildConfigSwiftDemo/Sources/UI/ContentView.swift b/Demo/BuildConfigSwiftDemo/Sources/UI/ContentView.swift
index bdfcc90..a0f7cee 100644
--- a/Demo/BuildConfigSwiftDemo/Sources/UI/ContentView.swift
+++ b/Demo/BuildConfigSwiftDemo/Sources/UI/ContentView.swift
@@ -9,13 +9,13 @@
 import SwiftUI
 
 struct ContentView: View {
-    var config: BuildConfig = .default
+    @Environment(\.buildConfig) var config: BuildConfig
 
     var body: some View {
         VStack {
             Text("isDebug: \(String(config.isDebug))")
             Text("Environment: \(config.environment)")
-            Text("API version: \(config.apiVersion, format: .number)")
+            Text("API version: \(config.api.version, format: .number)")
             Text("PI: \(config.pi, format: .number)")
         }
     }
diff --git a/Demo/BuildConfigSwiftDemo/Sources/UI/DemoApp.swift b/Demo/BuildConfigSwiftDemo/Sources/UI/DemoApp.swift
index 3f48f7c..07dad3b 100644
--- a/Demo/BuildConfigSwiftDemo/Sources/UI/DemoApp.swift
+++ b/Demo/BuildConfigSwiftDemo/Sources/UI/DemoApp.swift
@@ -8,20 +8,13 @@
 
 import SwiftUI
 
-@main
 struct DemoApp: App {
+    static var buildConfig: BuildConfig = .default
+
     var body: some Scene {
         WindowGroup {
             ContentView()
+                .environment(\.buildConfig, Self.buildConfig)
         }
     }
 }
-
-// MARK: - For Debug
-#if DEBUG
-private extension DemoApp {
-    var isTesting: Bool {
-        ProcessInfo.processInfo.environment["XCTestConfigurationFilePath"] != nil
-    }
-}
-#endif
diff --git a/Demo/BuildConfigSwiftDemo/Sources/Util/BuildConfig+Environment.swift b/Demo/BuildConfigSwiftDemo/Sources/Util/BuildConfig+Environment.swift
new file mode 100644
index 0000000..fa36ac2
--- /dev/null
+++ b/Demo/BuildConfigSwiftDemo/Sources/Util/BuildConfig+Environment.swift
@@ -0,0 +1,20 @@
+//
+//  BuildConfig+Environment.swift
+//  BuildConfigSwiftDemo
+//
+//  Created by 417.72KI on 2023/10/09.
+//  Copyright © 2023 417.72KI. All rights reserved.
+//
+
+import SwiftUI
+
+struct BuildConfigKey: EnvironmentKey {
+    static let defaultValue = BuildConfig.default
+}
+
+extension EnvironmentValues {
+    var buildConfig: BuildConfig {
+        get { self[BuildConfigKey.self] }
+        set { self[BuildConfigKey.self] = newValue }
+    }
+}
diff --git a/Demo/BuildConfigSwiftDemo/Sources/main.swift b/Demo/BuildConfigSwiftDemo/Sources/main.swift
new file mode 100644
index 0000000..68838ae
--- /dev/null
+++ b/Demo/BuildConfigSwiftDemo/Sources/main.swift
@@ -0,0 +1,15 @@
+//
+//  main.swift
+//  BuildConfigSwiftDemo
+//
+//  Created by 417.72KI on 2023/10/09.
+//  Copyright © 2023 417.72KI. All rights reserved.
+//
+
+import SwiftUI
+
+if let clazz = NSClassFromString("FakeApp") as? any App.Type {
+    clazz.main()
+} else {
+    DemoApp.main()
+}
diff --git a/Demo/BuildConfigSwiftDemoTests/APIClientTests.swift b/Demo/BuildConfigSwiftDemoTests/APIClientTests.swift
new file mode 100644
index 0000000..f9940bd
--- /dev/null
+++ b/Demo/BuildConfigSwiftDemoTests/APIClientTests.swift
@@ -0,0 +1,64 @@
+//
+//  APIClientTests.swift
+//  BuildConfigSwiftDemoTests
+//
+//  Created by 417.72KI on 2023/10/05.
+//  Copyright © 2023 417.72KI. All rights reserved.
+//
+
+import XCTest
+import StubNetworkKit
+
+@testable import BuildConfigSwiftDemo
+
+final class APIClientTests: XCTestCase {
+    var config = BuildConfig.fake.api
+
+    var apiClient: APIClient!
+
+    override func setUpWithError() throws {
+        apiClient = APIClient(config: config,
+                              session: defaultStubSession)
+    }
+
+    override func tearDownWithError() throws {
+        clearStubs()
+    }
+
+    func testLogin() async throws {
+        stub { 
+            Scheme.is("https")
+            Host.is("localhost")
+            Path.is("/login")
+            Method.isPost()
+            Body.isJson(["id": "john_doe", "password": "password"])
+        }.responseJson(["access_token": "foo", "refresh_token": "bar"])
+
+        let response = try await apiClient.login(id: "john_doe",
+                                                 password: "password")
+        XCTAssertEqual("foo", response.accessToken)
+        XCTAssertEqual("bar", response.refreshToken)
+    }
+
+    @available(iOS 16.0, *)
+    func testSearch() async throws {
+        stub {
+            Scheme.is("https")
+            Host.is("localhost")
+            Path.is("/search")
+            Method.isGet()
+            QueryParams.contains(["text": "寿限無"])
+        }.responseJson([
+            "items": [
+                ["name": "foo"],
+                ["name": "bar"],
+                ["name": "baz"],
+            ]
+        ])
+
+        let response = try await apiClient.search("寿限無")
+        XCTAssertEqual(3, response.items.count)
+        XCTAssertEqual("foo", response.items.first?.name)
+        XCTAssertEqual("baz", response.items.last?.name)
+    }
+}
diff --git a/Demo/BuildConfigSwiftDemoTests/BuildConfigSwiftDemoTests.swift b/Demo/BuildConfigSwiftDemoTests/BuildConfigSwiftDemoTests.swift
index 54f6399..5e2c5f0 100644
--- a/Demo/BuildConfigSwiftDemoTests/BuildConfigSwiftDemoTests.swift
+++ b/Demo/BuildConfigSwiftDemoTests/BuildConfigSwiftDemoTests.swift
@@ -12,26 +12,19 @@ import XCTest
 final class BuildConfigTests: XCTestCase {
     func testDefault() {
         let buildConfig = BuildConfig.default
-        XCTAssertEqual(1, buildConfig.apiVersion)
-        XCTAssertEqual("develop", buildConfig.environment)
-        XCTAssertFalse(buildConfig.isDebug)
+        XCTAssertEqual(1, buildConfig.api.version)
+        XCTAssertEqual("api-dev.example.com", buildConfig.api.host)
+        XCTAssertEqual("debug", buildConfig.environment)
+        XCTAssertTrue(buildConfig.isDebug)
         XCTAssertEqual(3.14, buildConfig.pi, accuracy: 0.01)
     }
 
-    func testLoad() {
-        let buildConfig = BuildConfig.load(
-            from: #"""
-            {
-                "api_version": 100, 
-                "environment": "staging",
-                "is_debug": true,
-                "pi": 3.14
-            }
-            """#.data(using: .utf8)!
-        )
-        XCTAssertEqual(100, buildConfig.apiVersion)
+    func testLoad() throws {
+        let buildConfig = BuildConfig.fake
+        XCTAssertEqual(100, buildConfig.api.version)
+        XCTAssertEqual("localhost", buildConfig.api.host)
         XCTAssertEqual("staging", buildConfig.environment)
-        XCTAssertTrue(buildConfig.isDebug)
+        XCTAssertFalse(buildConfig.isDebug)
         XCTAssertEqual(3.14, buildConfig.pi, accuracy: 0.01)
     }
 }
diff --git a/Demo/BuildConfigSwiftDemoTests/FakeApp.swift b/Demo/BuildConfigSwiftDemoTests/FakeApp.swift
new file mode 100644
index 0000000..bdd4428
--- /dev/null
+++ b/Demo/BuildConfigSwiftDemoTests/FakeApp.swift
@@ -0,0 +1,25 @@
+//
+//  FakeApp.swift
+//  BuildConfigSwiftDemoTests
+//
+//  Created by 417.72KI on 2023/10/09.
+//  Copyright © 2023 417.72KI. All rights reserved.
+//
+
+import SwiftUI
+
+@objc(FakeApp)
+final class FakeApp: NSObject, App {
+    override init() { super.init() }
+
+    var body: some Scene {
+        WindowGroup {
+            Text("This is a fake app.")
+                .foregroundStyle(Color.white)
+                .frame(maxWidth: .infinity, maxHeight: .infinity)
+                .background {
+                    Color.black
+                }
+        }
+    }
+}
diff --git a/Demo/BuildConfigSwiftDemoTests/TestHelper.swift b/Demo/BuildConfigSwiftDemoTests/TestHelper.swift
new file mode 100644
index 0000000..e8f06d3
--- /dev/null
+++ b/Demo/BuildConfigSwiftDemoTests/TestHelper.swift
@@ -0,0 +1,30 @@
+//
+//  TestHelper.swift
+//  BuildConfigSwiftDemoTests
+//
+//  Created by 417.72KI on 2023/10/05.
+//  Copyright © 2023 417.72KI. All rights reserved.
+//
+
+import Foundation
+@testable import BuildConfigSwiftDemo
+
+final class TestHelper {
+    private init() {}
+}
+
+extension TestHelper {
+    static var bundle: Bundle { Bundle(for: self.self) }
+}
+
+extension TestHelper {
+    static func path(forResource name: String, ofType ext: String) -> String? {
+        bundle.path(forResource: name, ofType: ext)
+    }
+}
+
+extension BuildConfig {
+    static var fake: Self {
+        .load(from: TestHelper.path(forResource: "test_config", ofType: "json")!)
+    }
+}
diff --git a/Demo/BuildConfigSwiftDemoTests/test_config.json b/Demo/BuildConfigSwiftDemoTests/test_config.json
new file mode 100644
index 0000000..209b487
--- /dev/null
+++ b/Demo/BuildConfigSwiftDemoTests/test_config.json
@@ -0,0 +1,23 @@
+{
+    "api": {
+        "version": 100,
+        "host": "localhost",
+        "endpoint": {
+            "login": {
+                "path": "/login",
+                "method": "POST"
+            },
+            "profile": {
+                "path": "/profile",
+                "method": "GET"
+            },
+            "search": {
+                "path": "/search",
+                "method": "GET"
+            }
+        }
+    },
+    "environment": "staging",
+    "is_debug": false,
+    "pi": 3.14
+}
diff --git a/Demo/Resources/BuildConfig/.env/debug.yml b/Demo/Resources/BuildConfig/.env/debug.yml
deleted file mode 100644
index 09b6da3..0000000
--- a/Demo/Resources/BuildConfig/.env/debug.yml
+++ /dev/null
@@ -1,2 +0,0 @@
-is_debug: false
-environment: develop
diff --git a/Demo/Resources/BuildConfig/api.yml b/Demo/Resources/BuildConfig/api.yml
new file mode 100644
index 0000000..fea282a
--- /dev/null
+++ b/Demo/Resources/BuildConfig/api.yml
@@ -0,0 +1,13 @@
+api:
+  version: 1
+  host: localhost
+  endpoint:
+    login:
+      method: POST
+      path: /login
+    profile:
+      method: GET
+      path: /profile
+    search:
+      method: GET
+      path: /search
diff --git a/Demo/Resources/BuildConfig/base.yml b/Demo/Resources/BuildConfig/config.yml
similarity index 74%
rename from Demo/Resources/BuildConfig/base.yml
rename to Demo/Resources/BuildConfig/config.yml
index ffdd767..0824541 100644
--- a/Demo/Resources/BuildConfig/base.yml
+++ b/Demo/Resources/BuildConfig/config.yml
@@ -1,4 +1,3 @@
 is_debug: true
 environment: debug
-api_version: 1
 pi: 3.14
diff --git a/Demo/Resources/BuildConfig/debug/api.yml b/Demo/Resources/BuildConfig/debug/api.yml
new file mode 100644
index 0000000..f6b147b
--- /dev/null
+++ b/Demo/Resources/BuildConfig/debug/api.yml
@@ -0,0 +1,2 @@
+api:
+  host: api-dev.example.com
diff --git a/Demo/Resources/BuildConfig/debug/config.yml b/Demo/Resources/BuildConfig/debug/config.yml
new file mode 100644
index 0000000..3e0d81f
--- /dev/null
+++ b/Demo/Resources/BuildConfig/debug/config.yml
@@ -0,0 +1,2 @@
+is_debug: true
+environment: debug
diff --git a/Demo/Resources/BuildConfig/integration_test/api.yml b/Demo/Resources/BuildConfig/integration_test/api.yml
new file mode 100644
index 0000000..ff729de
--- /dev/null
+++ b/Demo/Resources/BuildConfig/integration_test/api.yml
@@ -0,0 +1,2 @@
+api:
+  host: api-staging.example.com
diff --git a/Demo/Resources/BuildConfig/.env/integration_test.yml b/Demo/Resources/BuildConfig/integration_test/config.yml
similarity index 100%
rename from Demo/Resources/BuildConfig/.env/integration_test.yml
rename to Demo/Resources/BuildConfig/integration_test/config.yml
diff --git a/Demo/Resources/BuildConfig/release/api.yml b/Demo/Resources/BuildConfig/release/api.yml
new file mode 100644
index 0000000..44a1411
--- /dev/null
+++ b/Demo/Resources/BuildConfig/release/api.yml
@@ -0,0 +1,2 @@
+api:
+  host: api.example.com
diff --git a/Demo/Resources/BuildConfig/.env/release.yml b/Demo/Resources/BuildConfig/release/config.yml
similarity index 100%
rename from Demo/Resources/BuildConfig/.env/release.yml
rename to Demo/Resources/BuildConfig/release/config.yml
diff --git a/Demo/project.yml b/Demo/project.yml
index 2e2a39b..c09b77b 100644
--- a/Demo/project.yml
+++ b/Demo/project.yml
@@ -17,6 +17,9 @@ packages:
   XCGLogger:
     url: https://github.com/DaveWoodCom/XCGLogger
     from: 7.0.1
+  StubNetworkKit:
+    url: https://github.com/417-72KI/StubNetworkKit.git
+    from: 0.3.0
   # SwiftLint:
   #   url: https://github.com/realm/SwiftLint
   #   from: 0.53.0
@@ -94,3 +97,4 @@ targets:
       DEVELOPMENT_TEAM: ""
     dependencies:
       - target: BuildConfigSwiftDemo
+      - package: StubNetworkKit
diff --git a/Sources/Common/File+Path.swift b/Sources/Common/File+Path.swift
index f520357..71a0b98 100644
--- a/Sources/Common/File+Path.swift
+++ b/Sources/Common/File+Path.swift
@@ -16,6 +16,10 @@ public extension File {
         ["json"].contains(pathExtension)
     }
 
+    var isYamlOrJson: Bool {
+        isYaml || isJson
+    }
+
     var isExcludedFile: Bool {
         ["xcfilelist"].contains(pathExtension)
     }
diff --git a/Sources/Parser/Parser.swift b/Sources/Parser/Parser.swift
index 23b00ff..7399905 100644
--- a/Sources/Parser/Parser.swift
+++ b/Sources/Parser/Parser.swift
@@ -14,20 +14,18 @@ public struct Parser {
 
 public extension Parser {
     func run(environment: String?, skipInvalidFile: Bool = true) throws -> Data {
-        let filePaths = try getFileList(at: directoryPath, environment: environment)
-        let environmentFiles = filePaths.filter { $0.components.contains(envDirComponent) }
-            .compactMap { File(path: $0) }
-        if let environment,
-           environmentFiles.isEmpty {
+        let files = try getFileList(at: directoryPath,
+                                    environment: environment)
+        if let environment, files.env.isEmpty {
             dumpWarn("No file for environment `\(environment)` in `\(directoryPath)`.")
         }
-        let otherFiles = filePaths.filter { !$0.components.contains(envDirComponent) }
-            .compactMap { File(path: $0) }
-        let environmentData = try parse(files: environmentFiles, skipInvalidFile: skipInvalidFile)
+        let baseData = try parse(files: files.base,
+                                 skipInvalidFile: skipInvalidFile)
             .reduce(AnyParsable()) { $0 + $1 }
-        let defaultData = try parse(files: otherFiles, skipInvalidFile: skipInvalidFile)
+        let environmentData = try parse(files: files.env,
+                                        skipInvalidFile: skipInvalidFile)
             .reduce(AnyParsable()) { $0 + $1 }
-        let result = defaultData + environmentData
+        let result = baseData + environmentData
         return try JSONSerialization.data(
             withJSONObject: result.rawValue,
             options: []
@@ -36,18 +34,17 @@ public extension Parser {
 }
 
 extension Parser {
-    func getFileList(at path: Path, environment: String? = nil) throws -> [Path] {
-        if path.lastComponent == envDirComponent {
-            if let environment {
-                return try path.children().filter { $0.lastComponentWithoutExtension == environment }
-            }
-            return []
-        }
-        return try path.children()
+    func getFileList(at path: Path, environment: String? = nil) throws -> (base: [File], env: [File]) {
+        let files = try path.children()
             .lazy
-            .filter { $0.lastComponent != dsStoreFileName }
-            .compactMap { $0.isDirectory ? try getFileList(at: $0, environment: environment) : [$0] }
-            .flatMap { $0 }
+            .filter(\.isValidFile)
+            .compactMap(File.init(path:))
+            .filter(\.isYamlOrJson) as [File]
+        guard let environment else { return (files, []) }
+        let envFiles = (path + environment).lazy
+            .compactMap(File.init(path:))
+            .filter(\.isYamlOrJson) as [File]
+        return (files, envFiles)
     }
 
     func detectParser(_ file: File) throws -> FileParser {
diff --git a/Sources/Parser/Util/Path+Extension.swift b/Sources/Parser/Util/Path+Extension.swift
new file mode 100644
index 0000000..4ab5ef7
--- /dev/null
+++ b/Sources/Parser/Util/Path+Extension.swift
@@ -0,0 +1,12 @@
+import Foundation
+import PathKit
+
+extension Path {
+    var isDsStore: Bool {
+        lastComponent == dsStoreFileName
+    }
+
+    var isValidFile: Bool {
+        isFile && !isDsStore
+    }
+}
diff --git a/Tests/ParserTests/ParserTests.swift b/Tests/ParserTests/ParserTests.swift
index 92b50b8..da131f9 100644
--- a/Tests/ParserTests/ParserTests.swift
+++ b/Tests/ParserTests/ParserTests.swift
@@ -18,7 +18,7 @@ final class ParserTests: XCTestCase {
                 XCTAssertNotNil(try parser.detectParser(file) as? JSonParser)
             }
             try context("invalid") {
-                let file = File(path: path + "test.txt")!
+                let file = File(path: path + "ignored.txt")!
                 XCTAssertThrowsError(try parser.detectParser(file)) {
                     if let e = $0 as? ParserError {
                         XCTAssertEqual(e, ParserError.invalidFile(file.path!))
@@ -35,27 +35,91 @@ final class ParserTests: XCTestCase {
         try context("\(path)") {
             try context("environment is nil") {
                 try context("detects 6 files") {
-                    let files = ["test.yaml", "test.json", "test.txt",
-                                 "d1/test.txt", "d2/test.txt", "d2/d1/test.txt"]
-                    let expected = files.map { path + $0 }.sorted()
-                    let actual = try parser.getFileList(at: path).sorted()
-                    XCTAssertEqual(try parser.getFileList(at: path).sorted(), expected, diff(between: expected, and: actual))
+                    let expected = (
+                        base: ["test.yaml", "test.json"],
+                        env: [] as [String]
+                    )
+                    let actual = try parser.getFileList(at: path)
+                    context("base") {
+                        let expected = expected.base
+                            .map(path.appending(_:))
+                            .sorted()
+                        let actual = actual.base
+                            .compactMap(\.path)
+                            .compactMap(Path.init(_:))
+                            .sorted()
+                        XCTAssertEqual(expected, actual, diff(between: expected.map(\.lastComponent), and: actual.map(\.lastComponent)))
+                    }
+                    context("env") {
+                        let expected = expected.env
+                            .map(path.appending(_:))
+                            .sorted()
+                        let actual = actual.env
+                            .compactMap(\.path)
+                            .compactMap(Path.init(_:))
+                            .sorted()
+                        XCTAssertEqual(expected, actual, diff(between: expected.map(\.lastComponent), and: actual.map(\.lastComponent)))
+                    }
                 }
             }
             try context("environment is staging") {
                 try context("detects 7 files") {
-                    let files = ["test.yaml", "test.json", "test.txt",
-                                 "d1/test.txt", "d2/test.txt", "d2/d1/test.txt", ".env/staging.json"]
-                    let expected = files.map { path + $0 }.sorted()
-                    XCTAssertEqual(try parser.getFileList(at: path, environment: "staging").sorted(), expected)
+                    let expected = (
+                        base: ["test.yaml", "test.json"],
+                        env: ["staging/test.json"]
+                    )
+                    let actual = try parser.getFileList(at: path,
+                                                        environment: "staging")
+                    context("base") {
+                        let expected = expected.base
+                            .map(path.appending(_:))
+                            .sorted()
+                        let actual = actual.base
+                            .compactMap(\.path)
+                            .compactMap(Path.init(_:))
+                            .sorted()
+                        XCTAssertEqual(expected, actual, diff(between: expected.map(\.lastComponent), and: actual.map(\.lastComponent)))
+                    }
+                    context("env") {
+                        let expected = expected.env
+                            .map(path.appending(_:))
+                            .sorted()
+                        let actual = actual.env
+                            .compactMap(\.path)
+                            .compactMap(Path.init(_:))
+                            .sorted()
+                        XCTAssertEqual(expected, actual, diff(between: expected.map(\.lastComponent), and: actual.map(\.lastComponent)))
+                    }
                 }
             }
             try context("environment is production") {
                 try context("detects 7 files") {
-                    let files = ["test.yaml", "test.json", "test.txt",
-                                 "d1/test.txt", "d2/test.txt", "d2/d1/test.txt", ".env/production.yaml"]
-                    let expected = files.map { path + $0 }.sorted()
-                    XCTAssertEqual(try parser.getFileList(at: path, environment: "production").sorted(), expected)
+                    let expected = (
+                        base: ["test.yaml", "test.json"],
+                        env: ["production/test.yaml"]
+                    )
+                    let actual = try parser.getFileList(at: path,
+                                                        environment: "production")
+                    context("base") {
+                        let expected = expected.base
+                            .map(path.appending(_:))
+                            .sorted()
+                        let actual = actual.base
+                            .compactMap(\.path)
+                            .compactMap(Path.init(_:))
+                            .sorted()
+                        XCTAssertEqual(expected, actual, diff(between: expected.map(\.lastComponent), and: actual.map(\.lastComponent)))
+                    }
+                    context("env") {
+                        let expected = expected.env
+                            .map(path.appending(_:))
+                            .sorted()
+                        let actual = actual.env
+                            .compactMap(\.path)
+                            .compactMap(Path.init(_:))
+                            .sorted()
+                        XCTAssertEqual(expected, actual, diff(between: expected.map(\.lastComponent), and: actual.map(\.lastComponent)))
+                    }
                 }
             }
         }
diff --git a/Tests/ParserTests/Resources/d1/test.txt b/Tests/ParserTests/Resources/debug/d1/ignored.yml
similarity index 100%
rename from Tests/ParserTests/Resources/d1/test.txt
rename to Tests/ParserTests/Resources/debug/d1/ignored.yml
diff --git a/Tests/ParserTests/Resources/d2/d1/test.txt b/Tests/ParserTests/Resources/debug/test.yml
similarity index 100%
rename from Tests/ParserTests/Resources/d2/d1/test.txt
rename to Tests/ParserTests/Resources/debug/test.yml
diff --git a/Tests/ParserTests/Resources/d2/test.txt b/Tests/ParserTests/Resources/ignored.txt
similarity index 100%
rename from Tests/ParserTests/Resources/d2/test.txt
rename to Tests/ParserTests/Resources/ignored.txt
diff --git a/Tests/ParserTests/Resources/test.txt b/Tests/ParserTests/Resources/invalid_env/ignored.yml
similarity index 100%
rename from Tests/ParserTests/Resources/test.txt
rename to Tests/ParserTests/Resources/invalid_env/ignored.yml
diff --git a/Tests/ParserTests/Resources/.env/production.yaml b/Tests/ParserTests/Resources/production/test.yaml
similarity index 100%
rename from Tests/ParserTests/Resources/.env/production.yaml
rename to Tests/ParserTests/Resources/production/test.yaml
diff --git a/Tests/ParserTests/Resources/.env/staging.json b/Tests/ParserTests/Resources/staging/test.json
similarity index 100%
rename from Tests/ParserTests/Resources/.env/staging.json
rename to Tests/ParserTests/Resources/staging/test.json
diff --git a/Tests/ParserTests/Util.swift b/Tests/ParserTests/Util.swift
index 85abcd4..19930e1 100644
--- a/Tests/ParserTests/Util.swift
+++ b/Tests/ParserTests/Util.swift
@@ -8,6 +8,12 @@ var path: Path {
     return Path(resourcePath)
 }
 
+extension Path {
+    func appending(_ path: String) -> Path {
+        self + path
+    }
+}
+
 extension XCTestCase {
     func context(_ name: String, block: () throws -> Void) rethrows {
         if let _ = ProcessInfo().environment["XCTestConfigurationFilePath"] {
diff --git a/Tests/buildconfigswiftTests/Resources/src/.env/production.yaml b/Tests/buildconfigswiftTests/Resources/src/production/API.yaml
similarity index 100%
rename from Tests/buildconfigswiftTests/Resources/src/.env/production.yaml
rename to Tests/buildconfigswiftTests/Resources/src/production/API.yaml
diff --git a/Tests/buildconfigswiftTests/Resources/src/.env/staging.json b/Tests/buildconfigswiftTests/Resources/src/staging/API.json
similarity index 100%
rename from Tests/buildconfigswiftTests/Resources/src/.env/staging.json
rename to Tests/buildconfigswiftTests/Resources/src/staging/API.json