extract creation of templateHead

Author: bigaru

src/services/refactors/convertStringOrTemplateLiteral.ts

@@ -15,14 +15,12 @@ namespace ts.refactor.convertStringOrTemplateLiteral {
         let node = getTokenAtPosition(file, startPosition);
         if (isParenthesizedExpression(node.parent) && isBinaryExpression(node.parent.parent)) node = node.parent.parent;
         const maybeBinary = getParentBinaryExpression(node);
-        // const maybeTemplateExpression = findAncestor(node, n => isTemplateExpression(n));
         const actions: RefactorActionInfo[] = [];
 
         if ((isBinaryExpression(maybeBinary) || isStringLiteral(maybeBinary)) && isStringConcatenationValid(maybeBinary)) {
             actions.push({ name: toTemplateLiteralActionName, description: toTemplateLiteralDescription });
         }
 
-        // if ((isNoSubstitutionTemplateLiteral(node) && !isTaggedTemplateExpression(node.parent)) || (maybeTemplateExpression && !isTaggedTemplateExpression(maybeTemplateExpression.parent))) {
         if (isTemplateLike(node)) {
             actions.push({ name: toStringConcatenationActionName, description: toStringConcatenationDescription });
         }
@@ -31,10 +29,14 @@ namespace ts.refactor.convertStringOrTemplateLiteral {
     }
 
     function isTemplateLike(node: Node) {
-        const isEmptyTL = isNoSubstitutionTemplateLiteral(node) && !isTaggedTemplateExpression(node.parent);
-        const is = (isTemplateHead(node) || isTemplateMiddleOrTemplateTail(node)) && !isTaggedTemplateExpression(node.parent.parent);
-        const ise = (isTemplateSpan(node.parent)) && !isTaggedTemplateExpression(node.parent.parent.parent);
-        return isEmptyTL || is || ise;
+        const isEmptyTemplate = isNoSubstitutionTemplateLiteral(node) && isNotTagged(node);
+        const isTemplate = (isTemplateHead(node) || isTemplateMiddleOrTemplateTail(node)) && isNotTagged(node.parent);
+        const isTemplateFromExpression = isTemplateSpan(node.parent) && isNotTagged(node.parent.parent);
+        return isEmptyTemplate || isTemplate || isTemplateFromExpression;
+    }
+
+    function isNotTagged(templateExpression: Node) {
+        return !isTaggedTemplateExpression(templateExpression.parent);
     }
 
     function getEditsForAction(context: RefactorContext, actionName: string): RefactorEditInfo | undefined {
@@ -126,26 +128,23 @@ namespace ts.refactor.convertStringOrTemplateLiteral {
         return [[node], isStringLiteral(node), true];
     }
 
-    function nodesToTemplate(nodes: Node[]) {
+    function createHead(nodes: Node[]): [number, TemplateHead] {
         let begin = 0;
-
         const head = createTemplateHead("");
-        const firstNode = nodes[0];
-        const spans: TemplateSpan[] = [];
 
-        if (isStringLiteral(firstNode)) {
-            head.text = firstNode.text;
+        while (begin < nodes.length && isStringLiteral(nodes[begin])) {
+            const next = nodes[begin] as StringLiteral;
+            head.text = head.text + next.text;
             begin++;
+        }
 
-            while (begin < nodes.length && isStringLiteral(nodes[begin])) {
-
-                const next = nodes[begin] as StringLiteral;
-                head.text = head.text + next.text;
-                begin++;
-            }
+        head.text = escapeText(head.text);
+        return [begin, head];
+    }
 
-            head.text = cleanString(head.text);
-        }
+    function nodesToTemplate(nodes: Node[]) {
+        const spans: TemplateSpan[] = [];
+        const [begin, head] = createHead(nodes);
 
         if (begin === nodes.length) {
             return createNoSubstitutionTemplateLiteral(head.text);
@@ -166,7 +165,7 @@ namespace ts.refactor.convertStringOrTemplateLiteral {
                     i++;
                 }
 
-                text = cleanString(text);
+                text = escapeText(text);
                 templatePart = i === nodes.length - 1 ? createTemplateTail(text) : createTemplateMiddle(text);
             }
             else {
@@ -180,7 +179,7 @@ namespace ts.refactor.convertStringOrTemplateLiteral {
         return createTemplateExpression(head, spans);
     }
 
-    function cleanString(content: string) {
+    function escapeText(content: string) {
         return content.replace("`", "\`").replace("\${", `$\\{`);
     }