Add a description in case the mismatch fails #138

llorllale · Jan 16, 2021 · 40f1101 · 40f1101
1 parent 64e2122
commit 40f1101
Show file tree

Hide file tree

Showing 2 changed files with 43 additions and 6 deletions.
diff --git a/src/main/java/org/llorllale/cactoos/matchers/Mismatches.java b/src/main/java/org/llorllale/cactoos/matchers/Mismatches.java
@@ -63,6 +63,16 @@
 public final class Mismatches<X, M extends Matcher<X>> extends
     TypeSafeDiagnosingMatcher<M> {
 
+    /**
+     * Expected key word.
+     */
+    private static final String EXPECTED = "Expected: ";
+
+    /**
+     * But was key word.
+     */
+    private static final String BUT_WAS = " but was: ";
+
     /**
      * The testing arguments for the target matcher.
      */
@@ -103,8 +113,8 @@ public Mismatches(
             new Joined(
                 new FormattedText("%n"),
                 new TextOf(""),
-                new Joined(new TextOf(""), new TextOf("Expected: "), expected),
-                new Joined(new TextOf(""), new TextOf(" but was: "), actual)
+                new Joined(new TextOf(""), new TextOf(Mismatches.EXPECTED), expected),
+                new Joined(new TextOf(""), new TextOf(Mismatches.BUT_WAS), actual)
             )
         );
     }
@@ -128,19 +138,23 @@ public void describeTo(final Description desc) {
             .appendValue(this.message);
     }
 
-    // @todo #106:30min Add a description in case the mismatch fails.
-    //  And then introduce some tests to validate that the description
-    //  is properly constructed.
     @Override
     protected boolean matchesSafely(final M matcher, final Description dsc) {
         boolean mismatch;
         try {
             new Assertion<>("", this.args, matcher).affirm();
             mismatch = false;
+            dsc.appendText(Mismatches.EXPECTED);
+            matcher.describeTo(dsc);
+            dsc.appendText(Mismatches.BUT_WAS);
+            matcher.describeMismatch(this.args, dsc);
         } catch (final AssertionError err) {
             mismatch = err.getMessage().equals(
                 new UncheckedText(this.message).asString()
             );
+            if (!mismatch) {
+                dsc.appendText(err.getMessage());
+            }
         }
         return mismatch;
     }

diff --git a/src/test/java/org/llorllale/cactoos/matchers/MismatchesTest.java b/src/test/java/org/llorllale/cactoos/matchers/MismatchesTest.java
@@ -27,7 +27,11 @@
 
 package org.llorllale.cactoos.matchers;
 
+import org.cactoos.Text;
 import org.cactoos.text.TextOf;
+import org.hamcrest.Description;
+import org.hamcrest.StringDescription;
+import org.hamcrest.core.IsEqual;
 import org.junit.jupiter.api.Test;
 
 /**
@@ -53,6 +57,25 @@ void mismatches() {
         ).affirm();
     }
 
+    /**
+     * Matcher prints the actual value(s) properly.
+     */
+    @Test
+    void describeActual() {
+        final Description description = new StringDescription();
+        new Mismatches<Text, IsText>(
+            new TextOf("e"),
+            new TextOf("Mismatches <a> with message <e>")
+        ).matchesSafely(
+            new IsText("e"), description
+        );
+        new Assertion<>(
+            "describes the matcher",
+            description.toString(),
+            new IsEqual<>("Expected: Text with value \"e\" but was: Text is \"e\"")
+        ).affirm();
+    }
+
     @Test
     void matches() {
         new Assertion<>(
@@ -61,7 +84,7 @@ void matches() {
             new Mismatches<>(
                 new IsText("a"),
                 "Mismatches <a> with message <expected>",
-                ""
+                "Expected: Text with value \"a\" but was: Text is \"a\""
            )
         ).affirm();
     }