Add isWarningOrError to DiagnosticKindAssert

Author: ascopes

java-compiler-testing/src/main/java/io/github/ascopes/jct/assertions/DiagnosticKindAssert.java

@@ -15,6 +15,7 @@
  */
 package io.github.ascopes.jct.assertions;
 
+import java.util.Set;
 import javax.annotation.Nullable;
 import javax.tools.Diagnostic.Kind;
 import org.apiguardian.api.API;
@@ -30,6 +31,30 @@
 public final class DiagnosticKindAssert
     extends AbstractEnumAssert<DiagnosticKindAssert, Kind> {
 
+  /**
+   * Kinds that we consider to be types of warnings.
+   */
+  static final Set<Kind> WARNING_DIAGNOSTIC_KINDS = Set.of(
+      Kind.WARNING,
+      Kind.MANDATORY_WARNING
+  );
+
+  /**
+   * Kinds that we consider to be types of error.
+   */
+  static final Set<Kind> ERROR_DIAGNOSTIC_KINDS = Set.of(
+      Kind.ERROR
+  );
+
+  /**
+   * Kinds that we consider to be types of warning or errors.
+   */
+  static final Set<Kind> WARNING_AND_ERROR_DIAGNOSTIC_KINDS = Set.of(
+      Kind.WARNING,
+      Kind.MANDATORY_WARNING,
+      Kind.ERROR
+  );
+
   /**
    * Initialize this assertion type.
    *
@@ -46,7 +71,19 @@ public DiagnosticKindAssert(@Nullable Kind value) {
    * @throws AssertionError if this value is null, or the value is not {@link Kind#ERROR}.
    */
   public DiagnosticKindAssert isError() {
-    return isAnyOf(Kind.ERROR);
+    return isAnyOfElements(ERROR_DIAGNOSTIC_KINDS);
+  }
+
+  /**
+   * Assert that the kind is {@link Kind#ERROR}, {@link Kind#WARNING}, or
+   * {@link Kind#MANDATORY_WARNING}.
+   *
+   * @return this assertion object.
+   * @throws AssertionError if this value is null, or the value is not any of {@link Kind#ERROR},
+   *                        {@link Kind#WARNING}, or {@link Kind#MANDATORY_WARNING}.
+   */
+  public DiagnosticKindAssert isWarningOrError() {
+    return isAnyOfElements(WARNING_AND_ERROR_DIAGNOSTIC_KINDS);
   }
 
   /**
@@ -57,7 +94,7 @@ public DiagnosticKindAssert isError() {
    *                        or {@link Kind#MANDATORY_WARNING}.
    */
   public DiagnosticKindAssert isWarning() {
-    return isAnyOf(Kind.WARNING, Kind.MANDATORY_WARNING);
+    return isAnyOfElements(WARNING_DIAGNOSTIC_KINDS);
   }
 
   /**

java-compiler-testing/src/main/java/io/github/ascopes/jct/assertions/JctCompilationAssert.java

@@ -19,13 +19,8 @@
 import static java.util.stream.Collectors.toUnmodifiableList;
 
 import io.github.ascopes.jct.compilers.JctCompilation;
-import io.github.ascopes.jct.diagnostics.TraceDiagnostic;
 import io.github.ascopes.jct.repr.DiagnosticListRepresentation;
-import java.util.List;
-import java.util.Set;
-import java.util.function.Predicate;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
+import java.util.Collection;
 import javax.annotation.Nullable;
 import javax.tools.Diagnostic.Kind;
 import javax.tools.JavaFileManager.Location;
@@ -41,21 +36,8 @@
  * @since 0.0.1
  */
 @API(since = "0.0.1", status = Status.STABLE)
-@SuppressWarnings("UnusedReturnValue")
-public final class JctCompilationAssert extends AbstractAssert<JctCompilationAssert, JctCompilation> {
-
-  private static final Set<Kind> WARNING_DIAGNOSTIC_KINDS = Stream
-      .of(Kind.WARNING, Kind.MANDATORY_WARNING)
-      .collect(Collectors.toUnmodifiableSet());
-
-  private static final Set<Kind> ERROR_DIAGNOSTIC_KINDS = Stream
-      .of(Kind.ERROR)
-      .collect(Collectors.toUnmodifiableSet());
-
-  private static final Set<Kind> WARNING_AND_ERROR_DIAGNOSTIC_KINDS = Stream
-      .of(WARNING_DIAGNOSTIC_KINDS, ERROR_DIAGNOSTIC_KINDS)
-      .flatMap(Set::stream)
-      .collect(Collectors.toUnmodifiableSet());
+public final class JctCompilationAssert extends
+    AbstractAssert<JctCompilationAssert, JctCompilation> {
 
   /**
    * Initialize this compilation assertion.
@@ -79,17 +61,11 @@ public JctCompilationAssert isSuccessful() {
       // If we have error diagnostics, add them to the error message to provide helpful debugging
       // information. If we are treating warnings as errors, then we want to include those in this
       // as well.
-      Predicate<TraceDiagnostic<?>> isErrorDiagnostic = actual.isFailOnWarnings()
-          ? diag -> WARNING_AND_ERROR_DIAGNOSTIC_KINDS.contains(diag.getKind())
-          : diag -> ERROR_DIAGNOSTIC_KINDS.contains(diag.getKind());
-
-      var diagnostics = actual
-          .getDiagnostics()
-          .stream()
-          .filter(isErrorDiagnostic)
-          .collect(toUnmodifiableList());
+      var diagnosticKinds = actual.isFailOnWarnings()
+          ? DiagnosticKindAssert.WARNING_AND_ERROR_DIAGNOSTIC_KINDS
+          : DiagnosticKindAssert.ERROR_DIAGNOSTIC_KINDS;
 
-      failWithDiagnostics(diagnostics, "Expected a successful compilation, but it failed.");
+      failWithDiagnostics(diagnosticKinds, "Expected a successful compilation, but it failed.");
     }
 
     return myself;
@@ -122,13 +98,12 @@ public JctCompilationAssert isFailure() {
     isNotNull();
 
     if (actual.isSuccessful()) {
-      var warnings = actual
-          .getDiagnostics()
-          .stream()
-          .filter(kind -> WARNING_DIAGNOSTIC_KINDS.contains(kind.getKind()))
-          .collect(toUnmodifiableList());
-
-      failWithDiagnostics(warnings, "Expected compilation to fail, but it succeeded.");
+      // If we have any warnings, we should show them in the error message as it might be useful
+      // to the user.
+      failWithDiagnostics(
+          DiagnosticKindAssert.WARNING_DIAGNOSTIC_KINDS,
+          "Expected compilation to fail, but it succeeded."
+      );
     }
 
     return myself;
@@ -314,10 +289,16 @@ public ModuleContainerGroupAssert modulePath() {
   }
 
   private void failWithDiagnostics(
-      List<? extends TraceDiagnostic<?>> diagnostics,
+      Collection<? extends Kind> kindsToDisplay,
       String message,
       Object... args
   ) {
+    var diagnostics = actual
+        .getDiagnostics()
+        .stream()
+        .filter(diagnostic -> kindsToDisplay.contains(diagnostic.getKind()))
+        .collect(toUnmodifiableList());
+
     if (diagnostics.isEmpty()) {
       failWithMessage(message, args);
     } else {

java-compiler-testing/src/test/java/io/github/ascopes/jct/tests/unit/assertions/DiagnosticKindAssertTest.java

@@ -65,6 +65,48 @@ void isErrorSucceedsIfTheKindIsAnError() {
     }
   }
 
+  @DisplayName("DiagnosticKindAssert#isWarningOrError tests")
+  @Nested
+  class IsWarningOrErrorTest {
+
+    @DisplayName(
+        ".isWarningOrError() fails if the kind is not an error, warning, or mandatory warning"
+    )
+    @NullSource
+    @EnumSource(
+        value = Kind.class, 
+        mode = Mode.EXCLUDE, 
+        names = {"ERROR", "WARNING", "MANDATORY_WARNING"}
+    )
+    @ParameterizedTest(name = "for {0}")
+    void isWarningOrErrorFailsIfKindIsNotWarningOrError(Kind kind) {
+      // Given
+      var assertions = new DiagnosticKindAssert(kind);
+
+      // Then
+      assertThatThrownBy(assertions::isWarningOrError)
+          .isInstanceOf(AssertionError.class);
+    }
+
+    @DisplayName(
+        ".isWarningOrError() succeeds if the kind is an error, warning, or mandatory warning"
+    )
+    @EnumSource(
+        value = Kind.class,
+        mode = Mode.INCLUDE,
+        names = {"ERROR", "WARNING", "MANDATORY_WARNING"}
+    )
+    @ParameterizedTest(name = "for {0}")
+    void isWarningOrErrorSucceedsIfTheKindIsWarningOrError(Kind kind) {
+      // Given
+      var assertions = new DiagnosticKindAssert(kind);
+
+      // Then
+      assertThat(assertions.isWarningOrError())
+          .isSameAs(assertions);
+    }
+  }
+  
   @DisplayName("DiagnosticKindAssert#isWarning tests")
   @Nested
   class IsWarningTest {