fix(glimmer): preserve leading/trailing spaces in text nodes undernea… (#4288)

* fix(glimmer): preserve leading/trailing spaces in text nodes underneath attribute nodes when next to mustache statements.

* fix(glimmer): format printer-glimmer.js

* fix(glimmer): lint fix

* fix(glimmer): removed decomposition assignments to be compatible with Node 4

* fix(glimmer): Array.includes() -> indexOf() for Node 4

src/language-handlebars/printer-glimmer.js

@@ -193,7 +193,37 @@ function print(path, options, print) {
       return concat([n.key, "=", path.call(print, "value")]);
     }
     case "TextNode": {
-      return n.chars.replace(/^\s+/, "").replace(/\s+$/, "");
+      let leadingSpace = "";
+      let trailingSpace = "";
+
+      // preserve a space inside of an attribute node where whitespace present, when next to mustache statement.
+      const inAttrNode = path.stack.indexOf("attributes") >= 0;
+
+      if (inAttrNode) {
+        const parentNode = path.getParentNode(0);
+        const isConcat = parentNode.type === "ConcatStatement";
+        if (isConcat) {
+          const parts = parentNode.parts;
+          const partIndex = parts.indexOf(n);
+          if (partIndex > 0) {
+            const partType = parts[partIndex - 1].type;
+            const isMustache = partType === "MustacheStatement";
+            if (isMustache) {
+              leadingSpace = " ";
+            }
+          }
+          if (partIndex < parts.length - 1) {
+            const partType = parts[partIndex + 1].type;
+            const isMustache = partType === "MustacheStatement";
+            if (isMustache) {
+              trailingSpace = " ";
+            }
+          }
+        }
+      }
+      return n.chars
+        .replace(/^\s+/, leadingSpace)
+        .replace(/\s+$/, trailingSpace);
     }
     case "MustacheCommentStatement": {
       const dashes = n.value.indexOf("}}") > -1 ? "--" : "";

tests/html_glimmer/__snapshots__/jsfmt.spec.js.snap

@@ -118,21 +118,45 @@ exports[`concat-statement.hbs 1`] = `
 </div>
 
 <a href="/{{url}}/{{url}}"></a>
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-<div class="hello{{if goodbye true}}">
+
+<div class="  class-a{{myClass}}"></div>
+<div class=" class-b {{myClass}}"></div>
+<div class="    {{myClass}}class-c"></div>
+<div class="  {{myClass}}   class-d"></div>
+<div class=" class-e{{myClass}}    class-f"></div>
+<div class="     class-g{{myClass}}class-h    "></div>
+<div class=" class-i       {{myClass}}class-j"></div>
+<div class="class-k {{myClass}}   class-l"></div>
+<div class="  class-m   {{myClass}}     class-n {{myClass}}class-o   "></div>
+<div class="  class-p  class-q"></div>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+<div class="hello {{if goodbye true}}">
   Hello
 </div>
 <div
   class="hello
     {{if goodbye true}}
+
     {{if goodbye false}}
+
     {{if goodbye true}}
+
     {{if goodbye false}}
+
     {{if goodbye true}}"
 >
   Hello
 </div>
 <a href="/{{url}}/{{url}}"></a>
+<div class="class-a{{myClass}}"></div>
+<div class="class-b {{myClass}}"></div>
+<div class="{{myClass}}class-c"></div>
+<div class="{{myClass}} class-d"></div>
+<div class="class-e{{myClass}} class-f"></div>
+<div class="class-g{{myClass}}class-h"></div>
+<div class="class-i {{myClass}}class-j"></div>
+<div class="class-k {{myClass}} class-l"></div>
+<div class="class-m {{myClass}} class-n {{myClass}}class-o"></div>
+<div class="class-p  class-q"></div>
 `;
 
 exports[`element-modifier-statement.hbs 1`] = `

tests/html_glimmer/concat-statement.hbs

@@ -7,3 +7,14 @@
 </div>
 
 <a href="/{{url}}/{{url}}"></a>
+
+<div class="  class-a{{myClass}}"></div>
+<div class=" class-b {{myClass}}"></div>
+<div class="    {{myClass}}class-c"></div>
+<div class="  {{myClass}}   class-d"></div>
+<div class=" class-e{{myClass}}    class-f"></div>
+<div class="     class-g{{myClass}}class-h    "></div>
+<div class=" class-i       {{myClass}}class-j"></div>
+<div class="class-k {{myClass}}   class-l"></div>
+<div class="  class-m   {{myClass}}     class-n {{myClass}}class-o   "></div>
+<div class="  class-p  class-q"></div>