feat(kernel): distinguish framework errors from userland errors in Java

packages/@jsii/java-runtime-test/project/src/test/java/software/amazon/jsii/testing/ComplianceTest.java

@@ -6,6 +6,7 @@
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import software.amazon.jsii.ComplianceSuiteHarness;
+import software.amazon.jsii.JsException;
 import software.amazon.jsii.JsiiEngine;
 import software.amazon.jsii.JsiiException;
 import software.amazon.jsii.ReloadingClassLoader;
@@ -335,7 +336,7 @@ public void exceptions() {
         assertEquals(23, calc3.getValue());
         boolean thrown = false;
         try { calc3.add(10); }
-        catch (Exception e) { thrown = true; }
+        catch (JsException e) { thrown = true; }
         assertTrue(thrown);
         calc3.setMaxValue(40);
         calc3.add(10);
@@ -518,7 +519,7 @@ public String getTheProperty() {
         boolean thrown = false;
         try {
             so.retrieveValueOfTheProperty();
-        } catch (Exception e) {
+        } catch (JsiiException e) {
             assertTrue(e.getMessage().contains("Oh no, this is bad"));
             thrown = true;
         }
@@ -536,7 +537,7 @@ public void setTheProperty(String value) {
         boolean thrown = false;
         try {
             so.modifyValueOfTheProperty("Hii");
-        } catch (Exception e) {
+        } catch (JsiiException e) {
             assertTrue(e.getMessage().contains("Exception from overloaded setter"));
             thrown = true;
         }

packages/@jsii/java-runtime/project/src/main/java/software/amazon/jsii/JsException.java

@@ -0,0 +1,33 @@
+package software.amazon.jsii;
+
+/*
+ * Represents an irrecoverable error, such as a
+ * broken pipe.
+ */
+public final class JsException extends JsiiBaseException {
+
+  /**
+   * Creates an exception.
+   * @param message The error message
+   */
+  JsException(final String message) {
+      super(message);
+  }
+
+  /**
+   * Creates an exception.
+   * @param e The error that caused this exception
+   */
+  JsException(final Throwable e) {
+      super(e);
+  }
+
+  /**
+   * Creates an exception.
+   * @param message The error message
+   * @param e The error that caused this exception
+   */
+  JsException(final String message, final Throwable e) {
+      super(message, e);
+  }
+}

packages/@jsii/java-runtime/project/src/main/java/software/amazon/jsii/JsiiBaseException.java

@@ -0,0 +1,47 @@
+package software.amazon.jsii;
+
+/**
+ * An error raised by the jsii runtime.
+ */
+public abstract class JsiiBaseException extends RuntimeException {
+    public static enum Type {
+        JSII_FAULT("@jsii/kernel.Fault"),
+        JS_EXCEPTION("@jsii/kernel.JSError");
+
+        private final String errorType;
+
+        Type(String str) {
+            this.errorType = str;
+        }
+
+        public String toString() {
+            return this.errorType;
+        }
+    }
+    public static final long serialVersionUID = 1L;
+
+    /**
+     * Creates an exception.
+     * @param message The error message
+     */
+    JsiiBaseException(final String message) {
+        super(message);
+    }
+
+    /**
+     * Creates an exception.
+     * @param e The error that caused this exception
+     */
+    JsiiBaseException(final Throwable e) {
+        super(e);
+    }
+
+    /**
+     * Creates an exception.
+     * @param message The error message
+     * @param e The error that caused this exception
+     */
+    JsiiBaseException(final String message, final Throwable e) {
+        super(message, e);
+    }
+}

packages/@jsii/java-runtime/project/src/main/java/software/amazon/jsii/JsiiException.java

@@ -1,33 +1,32 @@
 package software.amazon.jsii;
 
-/**
- * An error raised by the jsii runtime.
+/*
+ * Represents an irrecoverable error, likely thrown from the kernel.
  */
-public final class JsiiException extends RuntimeException {
-    public static final long serialVersionUID = 1L;
+public final class JsiiException extends JsiiBaseException {
 
-    /**
-     * Creates an exception.
-     * @param message The error message
-     */
-    JsiiException(final String message) {
-        super(message);
-    }
+  /**
+   * Creates an exception.
+   * @param message The error message
+   */
+  JsiiException(final String message) {
+      super(message);
+  }
 
-    /**
-     * Creates an exception.
-     * @param e The error that caused this exception
-     */
-    JsiiException(final Throwable e) {
-        super(e);
-    }
+  /**
+   * Creates an exception.
+   * @param e The error that caused this exception
+   */
+  JsiiException(final Throwable e) {
+      super(e);
+  }
 
-    /**
-     * Creates an exception.
-     * @param message The error message
-     * @param e The error that caused this exception
-     */
-    JsiiException(final String message, final Throwable e) {
-        super(message, e);
-    }
+  /**
+   * Creates an exception.
+   * @param message The error message
+   * @param e The error that caused this exception
+   */
+  JsiiException(final String message, final Throwable e) {
+      super(message, e);
+  }
 }

packages/@jsii/java-runtime/project/src/main/java/software/amazon/jsii/JsiiRuntime.java

@@ -110,17 +110,22 @@ JsonNode requestResponse(final JsonNode request) {
 
     /**
      * Handles an "error" response by extracting the message and stack trace
-     * and throwing a JsiiException.
+     * and throwing a JsiiException or a JsException.
      *
      * @param resp The response
      * @return Never
      */
     private JsonNode processErrorResponse(final JsonNode resp) {
+        String errorName = resp.get("name").asText();
         String errorMessage = resp.get("error").asText();
         if (resp.has("stack")) {
             errorMessage += "\n" + resp.get("stack").asText();
         }
 
+        if (errorName.equals(JsiiException.Type.JS_EXCEPTION.toString())) {
+          throw new JsException(errorMessage);
+        }
+
         throw new JsiiException(errorMessage);
     }