#456: make content transfer encoder detection more lenient

Author: bbottema

modules/core-module/src/main/java/org/simplejavamail/api/email/ContentTransferEncoding.java

@@ -2,6 +2,7 @@
 
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
+import lombok.val;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Arrays;
@@ -30,10 +31,14 @@ public enum ContentTransferEncoding {
 	private final String encoder;
 
 	public static ContentTransferEncoding byEncoder(@NotNull final String encoder) {
-		return Arrays.stream(values())
-				.filter(c -> c.encoder.equalsIgnoreCase(encoder))
-				.findFirst()
-				.orElseThrow(() -> new IllegalArgumentException("unknown content transfer encoder: " + encoder));
+		try {
+			return ContentTransferEncoding.valueOf(encoder.replaceAll("-", "_").toUpperCase());
+		} catch (IllegalArgumentException e) {
+			return Arrays.stream(values())
+					.filter(c -> c.encoder.equalsIgnoreCase(encoder.replaceAll("_", "-")))
+					.findFirst()
+					.orElseThrow(() -> new IllegalArgumentException("unknown content transfer encoder: " + encoder));
+		}
 	}
 
 	@Override

modules/simple-java-mail/src/test/java/org/simplejavamail/api/email/ContentTransferEncodingTest.java

@@ -0,0 +1,22 @@
+package org.simplejavamail.api.email;
+
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+public class ContentTransferEncodingTest {
+
+    @Test
+    public void byEncoder() {
+        assertThat(ContentTransferEncoding.byEncoder("BASE_64")).isEqualTo(ContentTransferEncoding.BASE_64);
+        assertThat(ContentTransferEncoding.byEncoder("B")).isEqualTo(ContentTransferEncoding.B);
+        assertThat(ContentTransferEncoding.byEncoder("b")).isEqualTo(ContentTransferEncoding.B);
+        assertThat(ContentTransferEncoding.byEncoder("x-uuencode")).isEqualTo(ContentTransferEncoding.X_UU);
+        assertThat(ContentTransferEncoding.byEncoder("x_uuencode")).isEqualTo(ContentTransferEncoding.X_UU);
+        assertThat(ContentTransferEncoding.byEncoder("QUOTED-PRINTABLE")).isEqualTo(ContentTransferEncoding.QUOTED_PRINTABLE);
+        assertThatThrownBy(() -> ContentTransferEncoding.byEncoder("moomoo"))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessage("unknown content transfer encoder: moomoo");
+    }
+}