Fix exception wrapping to retain original message (#1265)

* added the parameterised error handling

* _

* added junit tests for the ZinggClientException class

* _

* _

* remote redundent printstacktrace

* error messages changed

Author: LOGANBLUE1

common/client/src/main/java/zingg/common/client/Client.java

@@ -62,8 +62,7 @@ public Client(IZArgs args, ClientOptions options, String zFactory) throws ZinggC
 			setZingg(args, options);					
 		}
 		catch (Exception e) {
-			e.printStackTrace();
-			throw new ZinggClientException("An error has occured while setting up the client" + e.getMessage());
+			throw new ZinggClientException("An error has occured while setting up the client", e);
 		}
 	}
 

common/client/src/main/java/zingg/common/client/ZinggClientException.java

@@ -10,22 +10,17 @@
 public class ZinggClientException extends Throwable {
 
 	private static final long serialVersionUID = 1L;
-	
-	public String message;
 
 	public ZinggClientException(String m) {
 		super(m);
-		this.message = m;
 	}
 
 	public ZinggClientException(String m, Throwable cause) {
 		super(m, cause);
-		this.message = m;
 	}
 
 	public ZinggClientException(Throwable cause) {
 		super(cause);
-		this.message = cause.getMessage();
 	}
 
 }

common/client/src/main/java/zingg/common/client/arguments/loader/template/TemplateFileArgumentLoader.java

@@ -23,8 +23,7 @@ public A load(String path) throws ZinggClientException {
             String substituted = substitutor.substitute(content, System.getenv());
             return objectMapper.readValue(substituted, argsClass);
         } catch (Exception | ZinggClientException exception) {
-            exception.printStackTrace();
-            throw new ZinggClientException("Unable to load template from: " + path);
+            throw new ZinggClientException("Unable to load template from: " + path, exception);
         }
     }
 }

common/client/src/main/java/zingg/common/client/arguments/writer/FileArgumentsWriter.java

@@ -12,7 +12,7 @@ public void write(String filePath, IZArgs args) throws ZinggClientException {
         try {
             objectMapper.writeValue(new File(filePath), args);
         } catch (Exception exception) {
-            throw new ZinggClientException("Error writing config to file: " + filePath);
+            throw new ZinggClientException("Error writing config to file: " + filePath, exception);
         }
     }
 }

common/client/src/main/java/zingg/common/client/util/vertical/VerticalDisplayUtility.java

@@ -47,7 +47,7 @@ public ZFrame<D, R, C> convertVertical(ZFrame<D, R, C> zFrame) throws ZinggClien
             }
             return dfObjectUtil.getDFFromObjectList(samples, VerticalDisplayTwoRowModel.class);
         } catch (Exception exception) {
-            throw new ZinggClientException("Error occurred while converting to vertical, " + exception.getMessage());
+            throw new ZinggClientException("Error occurred while converting to vertical, ", exception);
         }
     }
 

common/client/src/main/java/zingg/common/client/util/writer/PipeUtilWriter.java

@@ -18,7 +18,7 @@ public final void write(ZFrame<D, R, C> toWriteOrig, Pipe<D, R, C>... pipes) thr
                 writer.write(pipe);
             }
         } catch (Exception ex) {
-            throw new ZinggClientException(ex.getMessage());
+            throw new ZinggClientException("Error writing output", ex);
         }
     }
     protected abstract IDFWriter<D,R,C> getWriter(ZFrame<D, R, C> input, Pipe<D, R, C> pipe);

common/client/src/test/java/zingg/common/client/ZinggClientExceptionTest.java

@@ -0,0 +1,86 @@
+package zingg.common.client;
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+class ZinggClientExceptionTest {
+
+    @Test
+    void testMessageOnlyConstructor() {
+        String msg = "simple error";
+
+        ZinggClientException ex = new ZinggClientException(msg);
+
+        assertEquals(msg, ex.getMessage());
+        assertNull(ex.getCause());
+    }
+
+    @Test
+    void testMessageAndCauseConstructor() {
+        String msg = "wrapped error";
+        Throwable cause = new Exception("root cause");
+
+        ZinggClientException ex = new ZinggClientException(msg, cause);
+
+        assertEquals(msg, ex.getMessage());
+        assertNotNull(ex.getCause());
+        assertSame(cause, ex.getCause());
+        assertEquals("root cause", ex.getCause().getMessage());
+    }
+
+    @Test
+    void testCauseOnlyConstructor() {
+        Throwable cause = new Exception("original failure");
+
+        ZinggClientException ex = new ZinggClientException(cause);
+
+        assertEquals(cause.toString(), ex.getMessage());
+        assertNotNull(ex.getCause());
+        assertSame(cause, ex.getCause());
+    }
+
+    @Test
+    void testExceptionChainingDepth() {
+        Throwable root = new Exception("level 1");
+        ZinggClientException level2 = new ZinggClientException("level 2", root);
+        ZinggClientException level3 = new ZinggClientException("level 3", level2);
+
+        assertEquals("level 3", level3.getMessage());
+        assertSame(level2, level3.getCause());
+        assertSame(root, level3.getCause().getCause());
+        assertNull(level3.getCause().getCause().getCause());
+    }
+
+    @Test
+    void shouldPreserveMultipleExceptionLayers() {
+
+        ZinggClientException top =
+                assertThrows(ZinggClientException.class, () -> {
+
+                    try {
+                        try {
+                            throw new Exception("root exception");
+                        } catch (Exception e) {
+                            throw new ZinggClientException("level 1 exception", e);
+                        }
+                    } catch (ZinggClientException e) {
+                        throw new ZinggClientException("level 2 exception", e);
+                    }
+
+                });
+
+        assertEquals("level 2 exception", top.getMessage());
+
+        Throwable level1 = top.getCause();
+        assertNotNull(level1);
+        assertTrue(level1 instanceof ZinggClientException);
+        assertEquals("level 1 exception", level1.getMessage());
+
+        Throwable root = level1.getCause();
+        assertNotNull(root);
+        assertEquals(Exception.class, root.getClass());
+        assertEquals("root exception", root.getMessage());
+
+        assertNull(root.getCause());
+    }
+}

common/core/src/main/java/zingg/common/core/documenter/DataDocumenter.java

@@ -46,8 +46,7 @@ public void process() throws ZinggClientException {
 			}
 			LOG.info("Data document generation finishes");
 		} catch (Exception e) {
-			e.printStackTrace();
-			throw new ZinggClientException(e.getMessage());
+			throw new ZinggClientException("Error while documenting data ", e);
 		}
 	}
 

common/core/src/main/java/zingg/common/core/documenter/DocumenterBase.java

@@ -63,8 +63,7 @@ public void writeDocument(String template, Map<String, Object> root, String file
 			temp.process(root, file);
 			file.close();
 		} catch (Exception e) {
-			e.printStackTrace();
-			throw new ZinggClientException(e.getMessage());
+			throw new ZinggClientException("Error while writing document " + fileName, e);
 		}
 	}
 

common/core/src/main/java/zingg/common/core/documenter/ModelDocumenter.java

@@ -58,8 +58,7 @@ public void createModelDocument() throws ZinggClientException {
 
 			LOG.info("Model document generation finishes");
 		} catch (Exception e) {
-			e.printStackTrace();
-			throw new ZinggClientException(e.getMessage());
+			throw new ZinggClientException("Error while documenting model ", e);
 		}
 	}