From 7cc8302085f7b0add276670abcd214cb54fa9d27 Mon Sep 17 00:00:00 2001
From: Dan Freeman <dfreeman@salsify.com>
Date: Thu, 22 Jul 2021 16:31:45 +0200
Subject: [PATCH] Don't emit `parts: [undefined]` for `{{this}}`

---
 lib/helpers.js |  2 +-
 spec/ast.js    | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/lib/helpers.js b/lib/helpers.js
index c0f2865..323519c 100644
--- a/lib/helpers.js
+++ b/lib/helpers.js
@@ -86,7 +86,7 @@ export function preparePath(data, sexpr, parts, loc) {
     depth,
     head,
     tail,
-    parts: [head, ...tail],
+    parts: head ? [head, ...tail] : tail,
     original,
     loc
   };
diff --git a/spec/ast.js b/spec/ast.js
index a89e687..0fe4903 100644
--- a/spec/ast.js
+++ b/spec/ast.js
@@ -38,6 +38,38 @@ describe('ast', function() {
     });
   });
 
+  describe('node details', function () {
+    describe('paths', function () {
+      it('{{this}}', function () {
+        let path = parse('{{this}}').body[0].path;
+        equals(path.original, 'this');
+        equals(path.head, undefined);
+        equals(path.tail.length, 0);
+        equals(path.parts.length, 0);
+      });
+
+      it('{{this.bar}}', function () {
+        let path = parse('{{this.bar}}').body[0].path;
+        equals(path.original, 'this.bar');
+        equals(path.head, 'bar');
+        equals(path.tail.length, 0);
+        equals(path.parts.length, 1);
+        equals(path.parts[0], 'bar');
+      });
+
+      it('{{foo.bar}}', function () {
+        let path = parse('{{foo.bar}}').body[0].path;
+        equals(path.original, 'foo.bar');
+        equals(path.head, 'foo');
+        equals(path.tail.length, 1);
+        equals(path.tail[0], 'bar')
+        equals(path.parts.length, 2);
+        equals(path.parts[0], 'foo');
+        equals(path.parts[1], 'bar');
+      });
+    });
+  });
+
   describe('standalone flags', function() {
     describe('mustache', function() {
       it('does not mark mustaches as standalone', function() {