Add decoding of stack trace in JUnit adapter

core/src/main/resources/org/teavm/backend/javascript/runtime.js

@@ -248,6 +248,9 @@ function $rt_exception(ex) {
     var err = ex.$jsException;
     if (!err) {
         err = new Error("Java exception thrown");
+        if (typeof Error.captureStackTrace === "function") {
+            Error.captureStackTrace(err);
+        }
         err.$javaException = ex;
         ex.$jsException = err;
     }

tools/junit/src/main/java/org/teavm/junit/HtmlUnitRunStrategy.java

@@ -28,6 +28,7 @@ import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import net.sourceforge.htmlunit.corejs.javascript.Function;
 import net.sourceforge.htmlunit.corejs.javascript.NativeJavaObject;
+import net.sourceforge.htmlunit.corejs.javascript.Scriptable;
 import org.apache.commons.io.IOUtils;
 
 class HtmlUnitRunStrategy implements TestRunStrategy {
@@ -65,7 +66,9 @@ class HtmlUnitRunStrategy implements TestRunStrategy {
                 .getJavaScriptResult();
         Object[] args = new Object[] { new NativeJavaObject(function, asyncResult, AsyncResult.class) };
         page.get().executeJavaScriptFunctionIfPossible(function, function, args, page.get());
-        JavaScriptResultParser.parseResult((String) asyncResult.getResult(), run.getCallback());
+
+        RhinoResultParser.parseResult((Scriptable) asyncResult.getResult(), run.getCallback(),
+                new File(run.getBaseDirectory(), run.getFileName() + ".teavmdbg"));
     }
 
     private void cleanUp() {

tools/junit/src/main/java/org/teavm/junit/RhinoResultParser.java

@@ -0,0 +1,148 @@
+/*
+ *  Copyright 2018 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.junit;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import net.sourceforge.htmlunit.corejs.javascript.Scriptable;
+import org.teavm.debugging.information.DebugInformation;
+import org.teavm.debugging.information.SourceLocation;
+import org.teavm.model.MethodReference;
+
+final class RhinoResultParser {
+    private static Pattern pattern = Pattern.compile("(([A-Za-z_$]+)\\(\\))?@.+:([0-9]+)");
+    private static Pattern lineSeparator = Pattern.compile("\\r\\n|\r|\n");
+
+    private RhinoResultParser() {
+    }
+
+    static void parseResult(Scriptable result, TestRunCallback callback, File debugFile) {
+        if (result == null) {
+            callback.complete();
+            return;
+        }
+        String status = result.get("status", result).toString();
+        switch (status) {
+            case "ok":
+                callback.complete();
+                break;
+            case "exception": {
+                DebugInformation debugInformation = getDebugInformation(debugFile);
+
+                String className = String.valueOf(result.get("className", result));
+                String decodedName = debugInformation.getClassNameByJsName(className);
+                if (decodedName != null) {
+                    className = decodedName;
+                }
+                String message = String.valueOf(result.get("message", result));
+
+                String stack = result.get("stack", result).toString();
+                String[] script = getScript(new File(debugFile.getParentFile(),
+                        debugFile.getName().substring(0, debugFile.getName().length() - 9)));
+                stack = decodeStack(stack, script, debugInformation);
+
+                if (className.equals("java.lang.AssertionError")) {
+                    callback.error(new AssertionError(message + stack));
+                } else {
+                    callback.error(new RuntimeException(className + ": " + message + stack));
+                }
+                break;
+            }
+        }
+    }
+
+    private static String decodeStack(String stack, String[] script, DebugInformation debugInformation) {
+        StringBuilder sb = new StringBuilder();
+        for (String line : lineSeparator.split(stack)) {
+            sb.append("\n\tat ");
+            Matcher matcher = pattern.matcher(line);
+            if (!matcher.matches()) {
+                sb.append(line);
+                continue;
+            }
+
+            String functionName = matcher.group(2);
+            int lineNumber = Integer.parseInt(matcher.group(3)) - 1;
+
+            String scriptLine = script[lineNumber];
+            int column = firstNonSpace(scriptLine);
+            MethodReference method = debugInformation.getMethodAt(lineNumber, column);
+
+            if (method != null) {
+                sb.append(method.getClassName()).append(".").append(method.getName());
+            } else {
+                sb.append(functionName != null ? functionName : "<unknown_function>");
+            }
+
+            sb.append("(");
+            SourceLocation location = debugInformation.getSourceLocation(lineNumber, column);
+            if (location != null && location.getFileName() != null) {
+                String fileName = location.getFileName();
+                fileName = fileName.substring(fileName.lastIndexOf('/') + 1);
+                sb.append(fileName).append(":").append(location.getLine());
+            } else {
+                sb.append("test.js:").append(lineNumber + 1);
+            }
+            sb.append(")");
+        }
+
+        return sb.toString();
+    }
+
+    private static DebugInformation getDebugInformation(File debugFile) {
+        try (InputStream input = new FileInputStream(debugFile)) {
+            return DebugInformation.read(input);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private static String[] getScript(File file) {
+        List<String> lines = new ArrayList<>();
+        try (InputStream input = new FileInputStream(file);
+                Reader reader = new InputStreamReader(input, UTF_8);
+                BufferedReader bufferedReader = new BufferedReader(reader)) {
+            while (true) {
+                String line = bufferedReader.readLine();
+                if (line == null) {
+                    break;
+                }
+                lines.add(line);
+            }
+            return lines.toArray(new String[0]);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private static int firstNonSpace(String s) {
+        int i = 0;
+        while (i < s.length() && s.charAt(i) == ' ') {
+            i++;
+        }
+        return i;
+    }
+}

tools/junit/src/main/java/org/teavm/junit/TeaVMTestRunner.java

@@ -571,6 +571,7 @@ public class TeaVMTestRunner extends Runner implements Filterable {
         CompilePostProcessor postBuild = (vm, file) -> {
             DebugInformation debugInfo = debugEmitter.getDebugInformation();
             File sourceMapsFile = new File(file.getPath() + ".map");
+            File debugFile = new File(file.getPath() + ".teavmdbg");
             try {
                 try (Writer writer = new OutputStreamWriter(new FileOutputStream(file, true), UTF_8)) {
                     writer.write("\n//# sourceMappingURL=");
@@ -578,7 +579,11 @@ public class TeaVMTestRunner extends Runner implements Filterable {
                 }
 
                 try (Writer sourceMapsOut = new OutputStreamWriter(new FileOutputStream(sourceMapsFile), UTF_8)) {
-                    debugInfo.writeAsSourceMaps(sourceMapsOut, "src", file.getPath());
+                    debugInfo.writeAsSourceMaps(sourceMapsOut, "", file.getPath());
+                }
+
+                try (OutputStream out = new FileOutputStream(debugFile)) {
+                    debugInfo.write(out);
                 }
             } catch (IOException e) {
                 throw new RuntimeException(e);

tools/junit/src/main/resources/teavm-htmlunit-adapter.js

@@ -6,17 +6,19 @@ function runMain(callback) {
         } else {
             message.status = "ok";
         }
-        callback.complete(JSON.stringify(message));
+        callback.complete(message);
     });
 
     function makeErrorMessage(message, e) {
         message.status = "exception";
-        var stack = "";
-        if (e.$javaException && e.$javaException.constructor.$meta) {
-            stack = e.$javaException.constructor.$meta.name + ": ";
-            stack += e.$javaException.getMessage() || "";
-            stack += "\n";
+        if (e.$javaException) {
+            message.className = e.$javaException.constructor.name;
+            message.message = e.$javaException.getMessage();
+        } else {
+            message.className = Object.getPrototypeOf(e).name;
+            message.message = e.message;
         }
-        message.stack = stack + e.stack;
+        message.exception = e;
+        message.stack = e.stack;
     }
 }