From e84a1b0bae64a2952357f5c4f4c093a50ffccd65 Mon Sep 17 00:00:00 2001
From: Renaud Pawlak <renaud.pawlak@gmail.com>
Date: Thu, 4 Jun 2020 09:07:08 +0200
Subject: [PATCH] add parenthesis for binary/unary operator arguments when
 necessary

---
 .../transpiler/Java2TypeScriptTranslator.java |  3 +++
 .../extension/Java2TypeScriptAdapter.java     |  6 +++++
 .../transpiler/extension/PrinterAdapter.java  | 12 +++++++++
 .../transpiler/util/AbstractTreePrinter.java  | 26 +++++++++++++++++++
 4 files changed, 47 insertions(+)

diff --git a/transpiler/src/main/java/org/jsweet/transpiler/Java2TypeScriptTranslator.java b/transpiler/src/main/java/org/jsweet/transpiler/Java2TypeScriptTranslator.java
index e682070d..b34ca1a3 100644
--- a/transpiler/src/main/java/org/jsweet/transpiler/Java2TypeScriptTranslator.java
+++ b/transpiler/src/main/java/org/jsweet/transpiler/Java2TypeScriptTranslator.java
@@ -4949,10 +4949,12 @@ public class Java2TypeScriptTranslator extends AbstractTreePrinter {
 	}
 
 	protected void printBinaryRightOperand(JCBinary binary) {
+	    addInlinedExpression(binary.rhs);
 		print(binary.rhs);
 	}
 
 	protected void printBinaryLeftOperand(JCBinary binary) {
+        addInlinedExpression(binary.lhs);
 		print(binary.lhs);
 	}
 
@@ -5272,6 +5274,7 @@ public class Java2TypeScriptTranslator extends AbstractTreePrinter {
 	@Override
 	public void visitUnary(JCUnary unary) {
 		if (!getAdapter().substituteUnaryOperator(new UnaryOperatorElementSupport(unary))) {
+	        addInlinedExpression(unary.arg);
 			if (!inRollback) {
 				JCStatement statement = null;
 				VarSymbol[] staticInitializedField = { null };
diff --git a/transpiler/src/main/java/org/jsweet/transpiler/extension/Java2TypeScriptAdapter.java b/transpiler/src/main/java/org/jsweet/transpiler/extension/Java2TypeScriptAdapter.java
index d9165b42..81752945 100644
--- a/transpiler/src/main/java/org/jsweet/transpiler/extension/Java2TypeScriptAdapter.java
+++ b/transpiler/src/main/java/org/jsweet/transpiler/extension/Java2TypeScriptAdapter.java
@@ -1289,8 +1289,14 @@ public class Java2TypeScriptAdapter extends PrinterAdapter {
                         if (types().isSameType(invocationElement.getTargetExpression().getType(),
                                 util().getType(String.class))
                                 || util().isNumber(invocationElement.getTargetExpression().getType())) {
+                            if(isInlinedExpression(invocationElement)) {
+                                print("(");
+                            }
                             print(invocationElement.getTargetExpression()).print(" === ")
                                     .print(invocationElement.getArgument(0));
+                            if(isInlinedExpression(invocationElement)) {
+                                print(")");
+                            }
                         } else {
                             printMacroName(targetMethodName);
                             print("(<any>((o1: any, o2: any) => { if(o1 && o1.equals) { return o1.equals(o2); } else { return o1 === o2; } })(");
diff --git a/transpiler/src/main/java/org/jsweet/transpiler/extension/PrinterAdapter.java b/transpiler/src/main/java/org/jsweet/transpiler/extension/PrinterAdapter.java
index 3f299181..e4b1b85b 100644
--- a/transpiler/src/main/java/org/jsweet/transpiler/extension/PrinterAdapter.java
+++ b/transpiler/src/main/java/org/jsweet/transpiler/extension/PrinterAdapter.java
@@ -1177,4 +1177,16 @@ public class PrinterAdapter {
 	public final String getHeader(String key) {
 		return context.getHeader(key);
 	}
+
+    /**
+     * Tells if this element is an inlined expression. An inlined expression
+     * typically requires parenthesis (on contrary to top-level statement for instance).
+     * 
+     * @param element the element to check
+     * @return true if an inlined expression
+     */
+    public final boolean isInlinedExpression(ExtendedElement element) {
+        return printer.isInlinedExpression(((ExtendedElementSupport<?>) element).getTree());
+    }
+
 }
diff --git a/transpiler/src/main/java/org/jsweet/transpiler/util/AbstractTreePrinter.java b/transpiler/src/main/java/org/jsweet/transpiler/util/AbstractTreePrinter.java
index fbc6403e..3714b63e 100644
--- a/transpiler/src/main/java/org/jsweet/transpiler/util/AbstractTreePrinter.java
+++ b/transpiler/src/main/java/org/jsweet/transpiler/util/AbstractTreePrinter.java
@@ -18,7 +18,9 @@
  */
 package org.jsweet.transpiler.util;
 
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 import java.util.Stack;
 import java.util.function.Consumer;
 
@@ -51,6 +53,30 @@ public abstract class AbstractTreePrinter extends AbstractTreeScanner {
 
 	private Stack<Position> positionStack = new Stack<>();
 
+    private Set<JCTree> inlinedExpressions = new HashSet<JCTree>();
+
+    /**
+     * Tells if the given expression is an inlined expression 
+     * (and would require parenthesis).
+     */
+    public boolean isInlinedExpression(JCTree tree) {
+        return this.inlinedExpressions.contains(tree);
+    }
+    
+    /**
+     * Adds an inlined expression.
+     */
+    public void addInlinedExpression(JCTree tree) {
+        this.inlinedExpressions.add(tree);
+    }
+	
+    /**
+     * Clears the inlined expressions.
+     */
+    public void clearInlinedExpression() {
+        this.inlinedExpressions.clear();
+    }
+    
 	/**
 	 * A footer to be printed at the end of the output.
 	 */