Revert "[fix] Conjure Enum values support numeric characters (#197)"

This reverts commit 2acf798.

conjure-java-core/src/integrationInput/java/com/palantir/product/SimpleEnum.java

@@ -21,8 +21,6 @@
 public final class SimpleEnum {
     public static final SimpleEnum VALUE = new SimpleEnum(Value.VALUE, "VALUE");
 
-    public static final SimpleEnum VALUE2 = new SimpleEnum(Value.VALUE2, "VALUE2");
-
     private final Value value;
 
     private final String string;
@@ -59,8 +57,6 @@ public static SimpleEnum valueOf(String value) {
         switch (value) {
             case "VALUE":
                 return VALUE;
-            case "VALUE2":
-                return VALUE2;
             default:
                 ConjureEnums.validate(value);
                 return new SimpleEnum(Value.UNKNOWN, value);
@@ -71,8 +67,6 @@ public <T> T accept(Visitor<T> visitor) {
         switch (value) {
             case VALUE:
                 return visitor.visitValue();
-            case VALUE2:
-                return visitor.visitValue2();
             default:
                 return visitor.visitUnknown(string);
         }
@@ -82,17 +76,13 @@ public <T> T accept(Visitor<T> visitor) {
     public enum Value {
         VALUE,
 
-        VALUE2,
-
         UNKNOWN
     }
 
     @Generated("com.palantir.conjure.java.types.EnumGenerator")
     public interface Visitor<T> {
         T visitValue();
 
-        T visitValue2();
-
         T visitUnknown(String unknownValue);
     }
 }

conjure-java-core/src/test/java/com/palantir/conjure/java/types/WireFormatTests.java

@@ -209,7 +209,6 @@ public void testEnumCasingDeserializationInvariantToInputCase() throws Exception
                 .isInstanceOf(SafeIllegalArgumentException.class)
                 .hasLogMessage("Enum values must use UPPER_SNAKE_CASE")
                 .hasExactlyArgs(UnsafeArg.of("value", "oNE"));
-        assertThat(mapper.readValue("\"100\"", EnumExample.class)).isEqualTo(EnumExample.valueOf("100"));
     }
 
     private <T extends Throwable & SafeLoggable> LoggableExceptionAssert<T> assertThatExceptionThrownRootCause(

conjure-java-core/src/test/resources/ete-service.yml

@@ -13,7 +13,6 @@ types:
       SimpleEnum:
         values:
           - VALUE
-          - VALUE2
 
 services:
   EmptyPathService:

conjure-java-core/src/test/resources/example-types.yml

@@ -184,4 +184,3 @@ types:
       SimpleEnum:
         values:
           - VALUE
-          - VALUE2

conjure-lib/src/main/java/com/palantir/conjure/java/lib/internal/ConjureEnums.java

@@ -43,6 +43,6 @@ public static void validate(String value) {
     }
 
     private static boolean isAllowedCharacter(char character) {
-        return (character >= 'A' && character <= 'Z') || (character >= '0' && character <= '9') || character == '_';
+        return (character >= 'A' && character <= 'Z') || character == '_';
     }
 }