Test opinions (#2)

Add a test-focused library

.github/workflows/pr-test.yaml

@@ -18,5 +18,5 @@ jobs:
           java-version: "17"
           cache: "sbt"
       - name: Test Opinions
-        run: sbt opinions/test
+        run: sbt test
 

README.md

@@ -7,24 +7,28 @@ Scala 3 (and only Scala 3).
 
 ## Installation
 
-Check the badge above, or the latest GitHub release for the latest version.
+Check the badge above, or the latest GitHub release for the latest version
+to replace `x.y.z`.
 
 ### sbt
 
 ```scala
-libraryDependencies += "com.alterationx10" %% "opinionated-zio" % "0.0.1"
+libraryDependencies += "com.alterationx10" %% "opinionated-zio" % "x.y.z"
+libraryDependencies += "com.alterationx10" %% "opinionated-zio-test" % "x.y.z" % Test
 ```
 
 ### scala cli
 
 ```scala
-//> using lib com.alterationx10::opinionated-zio:v0.0.1
+//> using dep com.alterationx10::opinionated-zio:x.y.z
+//> using test.dep com.alterationx10::opinionated-zio-test:x.y.z
 ```
 
 ### mill
 
 ```scala
-ivy"com.alterationx10::opinionated-zio:v0.0.1"
+ivy"com.alterationx10::opinionated-zio:x.y.z"
+ivy"com.alterationx10::opinionated-zio-test:x.y.z"
 ```
 
 ## Example Usages
@@ -90,4 +94,15 @@ val superLayer: ZLayer[Int & Config, Nothing, Service] =
   AutoLayer.as[Service, ServiceImpl]
 
 
-```
+```
+
+## Example Test Library Usages
+
+Everything is bundled into one package for the test library as well, and to use
+it, you only need to
+
+```scala
+import test.opinons.*
+```
+
+More docs to come, but please check the corresponding tests for examples.

build.sbt

@@ -25,11 +25,19 @@ lazy val root = (project in file("."))
   .settings(
     publish / skip := true
   )
-  .aggregate(opinions)
+  .aggregate(opinions, testOpinions)
 
 lazy val opinions = (project in file("opinions"))
   .settings(
     name := "opinionated-zio",
     libraryDependencies ++= Dependencies.opinions,
     testFrameworks += new TestFramework("zio.test.sbt.ZTestFramework")
   )
+
+lazy val testOpinions = (project in file("test-opinions"))
+  .settings(
+    name := "opinionated-zio-test",
+    libraryDependencies ++= Dependencies.testOpinions,
+    testFrameworks += new TestFramework("zio.test.sbt.ZTestFramework")
+  )
+  .dependsOn(opinions)

opinions/src/main/scala/opinions/ZIO.scala

@@ -22,6 +22,10 @@ extension [Z: Tag](z: Z)
     */
   def uio: UIO[Z] = ZIO.succeed(z)
 
+  /** Wraps an instance z: Z in ZIO.fail
+    */
+  def fail: IO[Z, Nothing] = ZIO.fail(z)
+
 extension [R: Tag, E: Tag, A: Tag](zio: ZIO[R, E, A])
   /** Wraps a zio: ZIO[R, E, A] as ZLayer(zio)
     */

project/Dependencies.scala

@@ -20,4 +20,11 @@ object Dependencies {
     "dev.zio" %% "zio-config-typesafe" % Versions.zioConfig
   )
 
+  val testOpinions: Seq[ModuleID] = Seq(
+    "dev.zio" %% "zio-test"          % Versions.zio,
+    "dev.zio" %% "zio-test-sbt"      % Versions.zio,
+    "dev.zio" %% "zio-test-magnolia" % Versions.zio,
+    "dev.zio" %% "zio-mock"          % Versions.zioMock
+  )
+
 }

test-opinions/src/main/scala/test/opinions/Assertions.scala

@@ -0,0 +1,15 @@
+package test.opinions
+
+import zio.*
+import zio.test.*
+import opinions.*
+
+extension [A](a: A)
+
+  /** Wrap a: A in Assertion.equalTo(a)
+    */
+  def eqTo: Assertion[A] = Assertion.equalTo(a)
+
+  /** Wrap a: A in Assertion.not(Assertion.equalTo(a))
+    */
+  def neqTo: Assertion[A] = Assertion.not(a.eqTo)

test-opinions/src/main/scala/test/opinions/Expectations.scala

@@ -0,0 +1,14 @@
+package test.opinions
+
+import zio.*
+import zio.mock.*
+
+extension [A: Tag](a: A)
+
+  /** Wrap a: A in Expectation.value(a)
+    */
+  def expected: Result[Any, Nothing, A] = Expectation.value(a)
+
+  /** Wrap a: A in Expectation.failure(a)
+    */
+  def expectedF: Result[Any, A, Nothing] = Expectation.failure(a)

test-opinions/src/main/scala/test/opinions/Gens.scala

@@ -0,0 +1,24 @@
+package test.opinions
+
+import zio.test.*
+import zio.*
+
+object GenRandom:
+
+  /** Generate a random List[A]
+    * @param count
+    *   The number of elements to generate
+    * @param gen
+    *   The implicit Gen[Any, A] to use.
+    * @tparam A
+    */
+  def apply[A](count: Int)(using gen: Gen[Any, A]): UIO[List[A]] =
+    gen.runCollectN(count)
+
+  /** Generate a random A
+    * @param gen
+    *   The implicit Gen[Any, A] to use.
+    * @tparam A
+    */
+  def apply[A](using gen: Gen[Any, A]): UIO[A] =
+    GenRandom[A](1).map(_.head)

test-opinions/src/main/scala/test/opinions/Mocks.scala

@@ -0,0 +1,37 @@
+package test.opinions
+
+import zio.*
+import zio.mock.*
+import zio.test.Assertion
+
+extension [S, E: Tag, I, O: Tag](serviceMethod: Mock[S]#Effect[I, E, O])
+
+  /** For a given ZIO Mock Capability (serviceMethod), apply the given values as
+    * Expectation.value/Assertion.equalTo
+    * @param o
+    *   Expected output value
+    * @param i
+    *   Asserted input value
+    */
+  def expectWhen(o: O, i: I): Expectation[S] =
+    serviceMethod.apply(i.eqTo, o.expected)
+
+  /** For a given ZIO Mock Capability (serviceMethod), apply the given values as
+    * Expectation.failure/Assertion.equalTo
+    * @param e
+    *   Expected output failure value
+    * @param i
+    *   Asserted input value
+    */
+  def expectWhenF(e: E, i: I): Expectation[S] =
+    serviceMethod.apply(i.eqTo, e.expectedF)
+
+  /** For a given ZIO Mock Capability (serviceMethod), apply the given
+    * Expectation Result/Assertion
+    * @param o
+    *   The expected output Result/Expectation
+    * @param i
+    *   The expected input assertion
+    */
+  def expectWhen(o: Result[Any, E, O], i: Assertion[I]): Expectation[S] =
+    serviceMethod.apply(i, o)

test-opinions/src/test/scala/test/opinions/AssertionsSpec.scala

@@ -0,0 +1,16 @@
+package test.opinions
+
+import zio.*
+import zio.test.*
+import opinions.*
+
+object AssertionsSpec extends ZIOSpecDefault:
+  override def spec: Spec[TestEnvironment with Scope, Any] =
+    suite("AssertionsSpec")(
+      test("eqTo") {
+        assertZIO(42.uio)(42.eqTo)
+      },
+      test("neqTo") {
+        assertZIO(42.uio)(69.neqTo)
+      }
+    )

test-opinions/src/test/scala/test/opinions/ExpectationsSpec.scala

@@ -0,0 +1,17 @@
+package test.opinions
+
+import zio.*
+import zio.test.*
+import zio.mock.*
+
+object ExpectationsSpec extends ZIOSpecDefault:
+
+  override def spec: Spec[TestEnvironment with Scope, Any] =
+    suite("ExpectationsSpec")(
+      test("expected") {
+        assertZIO(42.expected.io(()))(42.eqTo)
+      },
+      test("expectedF") {
+        assertZIO(42.expectedF.io(()).flip)(42.eqTo)
+      }
+    )

test-opinions/src/test/scala/test/opinions/GensSpec.scala

@@ -0,0 +1,32 @@
+package test.opinions
+
+import zio.*
+import zio.test.*
+import opinions.*
+import zio.test.magnolia.DeriveGen
+
+import java.time.Instant
+import java.util.UUID
+
+object GensSpec extends ZIOSpecDefault:
+
+  case class SomeModel(a: Int, b: String, c: Instant, d: UUID)
+  given Gen[Any, SomeModel] = DeriveGen[SomeModel]
+
+  override def spec: Spec[TestEnvironment with Scope, Any] =
+    suite("GensSpec")(
+      test("Generate a random List of case class instances") {
+        for {
+          someNumber <- Random.nextIntBetween(10, 50)
+          models     <- GenRandom[SomeModel](someNumber)
+        } yield assertTrue(
+          models.length == someNumber,
+          models.distinct.length == someNumber
+        )
+      },
+      test("Generate a random instance of a case class") {
+        for {
+          model <- GenRandom[SomeModel]
+        } yield assertCompletes
+      }
+    )

test-opinions/src/test/scala/test/opinions/MocksSpec.scala

@@ -0,0 +1,71 @@
+package test.opinions
+
+import zio.*
+import zio.test.*
+import zio.mock.*
+import opinions.*
+
+object MocksSpec extends ZIOSpecDefault:
+
+  trait SomeService:
+    def get(id: Int): Task[String]
+
+  object SomeMockService extends Mock[SomeService]:
+    object Get extends Effect[Int, Throwable, String]
+
+    val compose: URLayer[Proxy, SomeService] =
+      ZLayer {
+        for {
+          proxy <- ZIO.service[Proxy]
+        } yield new SomeService:
+          override def get(id: RuntimeFlags): Task[String] = proxy(Get, id)
+      }
+  override def spec: Spec[TestEnvironment with Scope, Any] =
+    suite("MocksSpec + ")(
+      test("expectWhen of values") {
+        for {
+          result <- ZIO
+                      .serviceWithZIO[SomeService](_.get(42))
+                      .provide(SomeMockService.Get.expectWhen("forty two", 42))
+          _      <- ZIO
+                      .serviceWithZIO[SomeService](_.get(42))
+                      .provide(
+                        // Comparison without expectWhen extension method
+                        SomeMockService
+                          .Get(Assertion.equalTo(42), Expectation.value("forty two"))
+                      )
+        } yield assertTrue(result == "forty two")
+      },
+      test("expectWhenF of values") {
+        for {
+          error <-
+            ZIO
+              .serviceWithZIO[SomeService](_.get(42))
+              .flip
+              .provide(
+                SomeMockService.Get.expectWhenF(new Exception("boom"), 42)
+              )
+        } yield assertTrue(error.getMessage == "boom")
+      },
+      test("expectWhen of assertions") {
+        for {
+          result <-
+            ZIO
+              .serviceWithZIO[SomeService](_.get(42))
+              .provide(
+                SomeMockService.Get.expectWhen("forty two".expected, 42.eqTo)
+              )
+          error  <-
+            ZIO
+              .serviceWithZIO[SomeService](_.get(42))
+              .flip
+              .provide(
+                SomeMockService.Get
+                  .expectWhen(new Exception("boom").expectedF, 42.eqTo)
+              )
+        } yield assertTrue(
+          result == "forty two",
+          error.getMessage == "boom"
+        )
+      }
+    )