JSXTransformer, concatenate consecutive strings

src/dom/components/__tests__/ReactDOMTextarea-test.js

@@ -188,7 +188,7 @@ describe('ReactDOMTextarea', function() {
 
     expect(function() {
       ReactTestUtils.renderIntoDocument(
-        <textarea>{'hello'}{'there'}</textarea>
+        <textarea>{'hello'}{'there'+'avoid jsx concat'}</textarea>
       );
     }).toThrow();
 

vendor/fbtransform/transforms/react.js

@@ -50,6 +50,12 @@ var JSX_ATTRIBUTE_TRANSFORMS = {
   }
 };
 
+function isChildString(child) {
+  return child.type === Syntax.Literal ||
+    child.type === Syntax.XJSExpressionContainer &&
+    child.expression.raw && child.expression.raw.match(/^(|'[^']*'|"[^"]*")$/);
+}
+
 function visitReactTag(traverse, object, path, state) {
   var jsxObjIdent = utils.getDocblock(state).jsx;
 
@@ -134,18 +140,23 @@ function visitReactTag(traverse, object, path, state) {
   if (childrenToRender.length > 0) {
     utils.append(', ', state);
 
-    object.children.forEach(function(child) {
-      if (child.type === Syntax.Literal && !child.value.match(/\S/)) {
-        return;
-      }
+    childrenToRender.forEach(function(child, index) {
       utils.catchup(child.range[0], state);
 
-      var isLast = child === childrenToRender[childrenToRender.length - 1];
+      var isLast = index === childrenToRender.length - 1;
 
       if (child.type === Syntax.Literal) {
-        renderXJSLiteral(child, isLast, state);
+        var concat = !isLast && isChildString(childrenToRender[index + 1]);
+
+        renderXJSLiteral(child, isLast, state, null, null, concat);
       } else if (child.type === Syntax.XJSExpressionContainer) {
-        renderXJSExpressionContainer(traverse, child, isLast, path, state);
+        var concat = !isLast &&
+          isChildString(child) &&
+          isChildString(childrenToRender[index + 1]);
+
+        renderXJSExpressionContainer(
+          traverse, child, isLast, path, state, concat
+        );
       } else {
         traverse(child, path, state);
         if (!isLast) {

vendor/fbtransform/transforms/xjs.js

@@ -171,7 +171,7 @@ function trimWithSingleSpace(string) {
  *   "line "+
  *   "line"
  */
-function renderXJSLiteral(object, isLast, state, start, end) {
+function renderXJSLiteral(object, isLast, state, start, end, concat) {
   /** Added blank check filtering and triming*/
   var trimmedChildValue = safeTrim(object.value);
   var hasFinalNewLine = false;
@@ -253,7 +253,7 @@ function renderXJSLiteral(object, isLast, state, start, end) {
 
   // add comma before trailing whitespace
   if (!isLast) {
-    utils.append(',', state);
+    utils.append(concat ? '+' : ',', state);
   }
 
   // tail whitespace
@@ -264,14 +264,16 @@ function renderXJSLiteral(object, isLast, state, start, end) {
   utils.move(object.range[1], state);
 }
 
-function renderXJSExpressionContainer(traverse, object, isLast, path, state) {
+function renderXJSExpressionContainer(
+  traverse, object, isLast, path, state, concat
+) {
   // Plus 1 to skip `{`.
   utils.move(object.range[0] + 1, state);
   traverse(object.expression, path, state);
   if (!isLast && object.expression.type !== Syntax.XJSEmptyExpression) {
     // If we need to append a comma, make sure to do so after the expression.
     utils.catchup(object.expression.range[1], state);
-    utils.append(',', state);
+    utils.append(concat ? '+' : ',', state);
   }
 
   // Minus 1 to skip `}`.