#2772: PhContainingUTF8 to print strings correctly

eo-runtime/src/main/java/EOorg/EOeolang/EOerror.java

@@ -27,9 +27,13 @@
  */
 package EOorg.EOeolang;
 
+import java.nio.charset.StandardCharsets;
 import org.eolang.AtFree;
 import org.eolang.AtLambda;
 import org.eolang.Attr;
+import org.eolang.Bytes;
+import org.eolang.BytesOf;
+import org.eolang.Dataized;
 import org.eolang.ExAbstract;
 import org.eolang.ExFailure;
 import org.eolang.PhDefault;
@@ -115,7 +119,7 @@ public static final class ExError extends ExAbstract {
          * @param enclosure Enclosure inside the error
          */
         public ExError(final Phi enclosure) {
-            super(enclosure.toString());
+            super(EOerror.ExError.safeMessage(enclosure));
             this.enc = enclosure;
         }
 
@@ -126,5 +130,62 @@ public ExError(final Phi enclosure) {
         public Phi enclosure() {
             return this.enc;
         }
+
+        /**
+         * Retrieve message from enclosure safely.
+         * @param enclosure Enclosure.
+         * @return String message.
+         * @checkstyle IllegalCatchCheck (45 lines)
+         */
+        private static String safeMessage(final Phi enclosure) {
+            String result;
+            if (enclosure == null) {
+                result = "null Phi";
+            } else {
+                try {
+                    final byte[] data = new Dataized(enclosure).take();
+                    switch (data.length) {
+                        case 0:
+                            result = String.format(
+                                "%s(Δ = --)",
+                                enclosure
+                            );
+                            break;
+                        case 1:
+                            result = String.format(
+                                "%s(Δ = %s)",
+                                enclosure,
+                                data[0] > 0
+                            );
+                            break;
+                        case 8:
+                            final Bytes bytes = new BytesOf(data);
+                            result = String.format(
+                                "%s(Δ = %s = %s, or %s, or %s)",
+                                enclosure,
+                                bytes,
+                                bytes.asNumber(Long.class),
+                                bytes.asNumber(Double.class),
+                                new String(data, StandardCharsets.UTF_8)
+                            );
+                            break;
+                        default:
+                            result = String.format(
+                                "%s(Δ = %s or %s)",
+                                enclosure,
+                                new BytesOf(data),
+                                new String(data, StandardCharsets.UTF_8)
+                            );
+                    }
+                } catch (final Throwable first) {
+                    try {
+                        result = enclosure.toString();
+                    } catch (final Throwable second) {
+                        result = enclosure.getClass().toString();
+                    }
+                }
+            }
+            return result;
+        }
     }
 }

eo-runtime/src/test/java/EOorg/EOeolang/EOerrorTest.java

@@ -27,12 +27,22 @@
  */
 package EOorg.EOeolang;
 
+import java.util.stream.Stream;
+import org.eolang.AtComposite;
+import org.eolang.AtOnce;
 import org.eolang.Data;
 import org.eolang.Dataized;
+import org.eolang.ExAbstract;
+import org.eolang.PhCopy;
+import org.eolang.PhDefault;
 import org.eolang.PhWith;
 import org.eolang.Phi;
+import org.hamcrest.MatcherAssert;
+import org.hamcrest.Matchers;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
 
 /**
  * Test case for {@link EOerror}.
@@ -55,4 +65,67 @@ void makesToxicObject() {
         );
     }
 
+    @ParameterizedTest
+    @MethodSource("getTestSources")
+    void getsReadableError(final Object cnst) {
+        ExAbstract error = null;
+        try {
+            new Dataized(new MyError(cnst)).take();
+        } catch (final ExAbstract exc) {
+            error = exc;
+        }
+        assert error != null;
+        MatcherAssert.assertThat(
+            error.toString(),
+            Matchers.containsString(cnst.toString())
+        );
+    }
+
+    /**
+     * Input arguments for getsReadableError unit test.
+     * @return Stream of arguments.
+     */
+    private static Stream<Object> getTestSources() {
+        return Stream.of(
+            12345L,
+            "qwerty",
+            12.34567D,
+            true,
+            false
+        );
+    }
+
+    /**
+     * The object below.
+     * [] > my-error
+     *   error > @
+     *     "qwerty"
+     * @since 0.35
+     * @checkstyle JavadocStyleCheck
+     */
+    private static final class MyError extends PhDefault {
+
+        /**
+         * Ctor.
+         * @param data Data inside error.
+         */
+        MyError(final Object data) {
+            this.add(
+                "φ",
+                new AtOnce(
+                    new AtComposite(
+                        this,
+                        rho -> new PhWith(
+                            new PhCopy(
+                                Phi.Φ.attr("org").get().attr("eolang").get().attr("error").get()
+                            ),
+                            "α",
+                            new Data.ToPhi(data)
+                        )
+                    )
+                )
+            );
+        }
+    }
+
 }