From 02a4eed22daca9a9bca3342396fa1ef6a8427024 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stanis=C5=82aw=20Barzowski?= <sbarzowski@google.com>
Date: Mon, 2 Oct 2017 13:23:16 -0400
Subject: [PATCH] Support $ in comprehesions, fixes #68

---
 desugarer.go                         |  5 +++++
 testdata/object_comp_dollar.golden   |  5 +++++
 testdata/object_comp_dollar.jsonnet  |  1 +
 testdata/object_comp_dollar2.golden  | 14 ++++++++++++++
 testdata/object_comp_dollar2.jsonnet |  1 +
 testdata/object_comp_dollar3.golden  |  7 +++++++
 testdata/object_comp_dollar3.jsonnet |  3 +++
 7 files changed, 36 insertions(+)
 create mode 100644 testdata/object_comp_dollar.golden
 create mode 100644 testdata/object_comp_dollar.jsonnet
 create mode 100644 testdata/object_comp_dollar2.golden
 create mode 100644 testdata/object_comp_dollar2.jsonnet
 create mode 100644 testdata/object_comp_dollar3.golden
 create mode 100644 testdata/object_comp_dollar3.jsonnet

diff --git a/desugarer.go b/desugarer.go
index 0fe4351..148b4a2 100644
--- a/desugarer.go
+++ b/desugarer.go
@@ -228,6 +228,11 @@ func desugarArrayComp(comp *ast.ArrayComp, objLevel int) (ast.Node, error) {
 
 func desugarObjectComp(comp *ast.ObjectComp, objLevel int) (ast.Node, error) {
 
+	if objLevel == 0 {
+		dollar := ast.Identifier("$")
+		comp.Fields = append(comp.Fields, ast.ObjectFieldLocalNoMethod(&dollar, &ast.Self{}))
+	}
+
 	// TODO(sbarzowski) find a consistent convention to prevent desugaring the same thing twice
 	// here we deeply desugar fields and it will happen again
 	err := desugarFields(*comp.Loc(), &comp.Fields, objLevel+1)
diff --git a/testdata/object_comp_dollar.golden b/testdata/object_comp_dollar.golden
new file mode 100644
index 0000000..a488a32
--- /dev/null
+++ b/testdata/object_comp_dollar.golden
@@ -0,0 +1,5 @@
+{
+   "a": 42,
+   "b": 43,
+   "c": 43
+}
diff --git a/testdata/object_comp_dollar.jsonnet b/testdata/object_comp_dollar.jsonnet
new file mode 100644
index 0000000..44c8fe6
--- /dev/null
+++ b/testdata/object_comp_dollar.jsonnet
@@ -0,0 +1 @@
+{ [x]: if x == "a" then 42 else $.a + 1 for x in ["a", "b", "c"] }
diff --git a/testdata/object_comp_dollar2.golden b/testdata/object_comp_dollar2.golden
new file mode 100644
index 0000000..8762a12
--- /dev/null
+++ b/testdata/object_comp_dollar2.golden
@@ -0,0 +1,14 @@
+{
+   "a": {
+      "a": 1,
+      "b": 42
+   },
+   "b": {
+      "a": 1,
+      "b": 43
+   },
+   "c": {
+      "a": 1,
+      "b": 43
+   }
+}
diff --git a/testdata/object_comp_dollar2.jsonnet b/testdata/object_comp_dollar2.jsonnet
new file mode 100644
index 0000000..361b8ed
--- /dev/null
+++ b/testdata/object_comp_dollar2.jsonnet
@@ -0,0 +1 @@
+{ [x]: { a: 1, b: if x == "a" then 42 else $.a.b + 1 } for x in ["a", "b", "c"] }
diff --git a/testdata/object_comp_dollar3.golden b/testdata/object_comp_dollar3.golden
new file mode 100644
index 0000000..ec532ea
--- /dev/null
+++ b/testdata/object_comp_dollar3.golden
@@ -0,0 +1,7 @@
+{
+   "obj": {
+      "a": 1,
+      "b": 2,
+      "c": 2
+   }
+}
diff --git a/testdata/object_comp_dollar3.jsonnet b/testdata/object_comp_dollar3.jsonnet
new file mode 100644
index 0000000..e0a35ca
--- /dev/null
+++ b/testdata/object_comp_dollar3.jsonnet
@@ -0,0 +1,3 @@
+local obj = { [x]: if x == "a" then 42 else $.a + 1 for x in ["a", "b", "c"] };
+{ obj: obj + {a: 1} }
+