Added TestErrorBoundary to test module, fixed #4

test/src/main/scala/scommons/react/test/TestErrorBoundary.scala

@@ -0,0 +1,28 @@
+package scommons.react.test
+
+import scommons.react._
+
+import scala.scalajs.js
+
+object TestErrorBoundary extends ClassComponent[Unit] {
+
+  private case class TestErrorBoundaryState(error: Option[js.Object] = None)
+
+  protected def create(): ReactClass = createClass[TestErrorBoundaryState](
+    getInitialState = { _ =>
+      TestErrorBoundaryState()
+    },
+    componentDidCatch = { (self, error, _) =>
+      self.setState(TestErrorBoundaryState(Option(error)))
+    },
+    render = { self =>
+      self.state.error match {
+        case None => self.props.children
+        case Some(error) =>
+          <.div()(
+            s"$error"
+          )
+      }
+    }
+  )
+}

test/src/test/scala/scommons/react/test/TestErrorBoundarySpec.scala

@@ -0,0 +1,49 @@
+package scommons.react.test
+
+import scommons.react.{FunctionComponent, ReactElement}
+
+import scala.scalajs.js
+
+class TestErrorBoundarySpec extends TestSpec with TestRendererUtils {
+
+  it should "render children if no errors" in {
+    //when
+    val result = createTestRenderer(<(TestErrorBoundary())()(
+      "some child"
+    )).root
+
+    //then
+    inside(result.children.toList) { case List(child) =>
+      child shouldBe "some child"
+    }
+  }
+
+  it should "render error details if error during render" in {
+    //given
+    val errorComp = new FunctionComponent[Unit] {
+      protected def render(props: Props): ReactElement = {
+        throw new IllegalArgumentException("test error")
+      }
+    }
+
+    // suppress intended error
+    // see: https://github.com/facebook/react/issues/11098#issuecomment-412682721
+    val savedConsoleError = js.Dynamic.global.console.error
+    js.Dynamic.global.console.error = { _: js.Any =>
+    }
+
+    //when
+    val result = testRender(<(TestErrorBoundary())()(
+      <(errorComp())()()
+    ))
+
+    //then
+    js.Dynamic.global.console.error = savedConsoleError
+
+    assertNativeComponent(result,
+      <.div()(
+        "java.lang.IllegalArgumentException: test error"
+      )
+    )
+  }
+}