objectionary#3461 Add Expect for EOnumber$EOplus

asmirnov-backend · Jan 7, 2025 · 4e2e0ab · 4e2e0ab
1 parent c783fd2
commit 4e2e0ab
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Showing 2 changed files with 51 additions and 6 deletions.
diff --git a/eo-runtime/src/main/java/EOorg/EOeolang/EOnumber$EOplus.java b/eo-runtime/src/main/java/EOorg/EOeolang/EOnumber$EOplus.java
@@ -30,6 +30,7 @@
 
 import org.eolang.AtVoid;
 import org.eolang.Atom;
+import org.eolang.Expect;
 import org.eolang.Attr;
 import org.eolang.Data;
 import org.eolang.Dataized;
@@ -56,11 +57,11 @@ public final class EOnumber$EOplus extends PhDefault implements Atom {
 
     @Override
     public Phi lambda() {
-        return new Data.ToPhi(
-            Double.sum(
-                new Dataized(this.take(Attr.RHO)).asNumber(),
-                new Dataized(this.take("x")).asNumber()
-            )
-        );
+        Double left = new Dataized(this.take(Attr.RHO)).asNumber();
+        Double right = Expect.at(this, "x")
+            .that(phi -> new Dataized(phi).asNumber())
+            .otherwise("number.plus expects its second argument to be a number")
+            .it();
+        return new Data.ToPhi(Double.sum(left, right));
     }
 }
diff --git a/eo-runtime/src/test/java/EOorg/EOeolang/EOnumber$EOplusTest.java b/eo-runtime/src/test/java/EOorg/EOeolang/EOnumber$EOplusTest.java
@@ -0,0 +1,44 @@
+package EOorg.EOeolang;
+
+import org.eolang.Attr;
+import org.eolang.Data;
+import org.eolang.Dataized;
+import org.eolang.ExAbstract;
+import org.eolang.PhWith;
+import org.hamcrest.MatcherAssert;
+import org.hamcrest.Matchers;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test case for {@link EOnumber$EOplus}.
+ *
+ * @since 0.51
+ * @checkstyle TypeNameCheck (3 lines)
+ */
+@SuppressWarnings("PMD.AvoidDollarSigns")
+final class EOnumber$EOplusTest {
+
+    @Test
+    void throwsCorrectError() {
+        MatcherAssert.assertThat(
+            "the message in the error is correct",
+            Assertions.assertThrows(
+                ExAbstract.class,
+                () -> new Dataized(
+                    new PhWith(
+                        new PhWith(
+                            new EOnumber$EOplus(),
+                            Attr.RHO,
+                            new Data.ToPhi(42)
+                        ),
+                        "x",
+                        new Data.ToPhi(true)
+                    )
+                ).take(),
+                "addition with TRUE fails with a proper message that explains what happened"
+            ).getMessage(),
+            Matchers.containsString("number.plus expects its second argument to be a number")
+        );
+    }
+}