Merge pull request #1080 from jedevc/issue-1051

hclparser: strip out blocks for json files

bake/hcl_test.go

@@ -745,3 +745,13 @@ target "two" {
 	require.Equal(t, c.Targets[1].Name, "two")
 	require.Equal(t, map[string]string{"b": "pre-jkl"}, c.Targets[1].Args)
 }
+
+func TestEmptyVariableJSON(t *testing.T) {
+	dt := []byte(`{
+	  "variable": {
+	    "VAR": {}
+	  }
+	}`)
+	_, err := ParseFile(dt, "docker-bake.json")
+	require.NoError(t, err)
+}

bake/hclparser/hclparser.go

@@ -256,6 +256,7 @@ func Parse(b hcl.Body, opt Opt, val interface{}) hcl.Diagnostics {
 	if err := gohcl.DecodeBody(b, nil, &defs); err != nil {
 		return err
 	}
+	defsSchema, _ := gohcl.ImpliedBodySchema(defs)
 
 	if opt.LookupVar == nil {
 		opt.LookupVar = func(string) (string, bool) {
@@ -300,6 +301,16 @@ func Parse(b hcl.Body, opt Opt, val interface{}) hcl.Diagnostics {
 		p.funcs[v.Name] = v
 	}
 
+	content, b, diags := b.PartialContent(schema)
+	if diags.HasErrors() {
+		return diags
+	}
+
+	_, b, diags = b.PartialContent(defsSchema)
+	if diags.HasErrors() {
+		return diags
+	}
+
 	attrs, diags := b.JustAttributes()
 	if diags.HasErrors() {
 		if d := removeAttributesDiags(diags, reserved, p.vars); len(d) > 0 {
@@ -371,11 +382,6 @@ func Parse(b hcl.Body, opt Opt, val interface{}) hcl.Diagnostics {
 		}
 	}
 
-	content, _, diags := b.PartialContent(schema)
-	if diags.HasErrors() {
-		return diags
-	}
-
 	for _, a := range content.Attributes {
 		return hcl.Diagnostics{
 			&hcl.Diagnostic{