starlark/types: computed, fix proper MaxItem==1 indexes

Author: mcuadros

starlark/types/computed.go

@@ -23,6 +23,7 @@ func NewComputed(r *Resource, t cty.Type, name string) *Computed {
 	var path string
 
 	child := r
+
 	for {
 		if child.parent.kind == ProviderKind {
 			if child.kind == ResourceKind {
@@ -42,6 +43,12 @@ func NewComputed(r *Resource, t cty.Type, name string) *Computed {
 		path += "." + parts[i]
 	}
 
+	// handling of MaxItems equals 1
+	block, ok := r.parent.block.BlockTypes[r.typ]
+	if ok && block.MaxItems == 1 {
+		name = "0." + name
+	}
+
 	return NewComputedWithPath(r, t, name, path+"."+name)
 }
 

starlark/types/testdata/computed.star

@@ -22,10 +22,16 @@ assert.eq(str(instance.credit_specification[0].cpu_credits), '"${data.aws_instan
 
 # compute of map
 computed = str(aws.resource.instance().root_block_device.volume_size)
-assert.eq(computed, '"${aws_instance.id_6.root_block_device.volume_size}"')
+assert.eq(computed, '"${aws_instance.id_6.root_block_device.0.volume_size}"')
 
 # compute on data source
 assert.eq(str(aws.resource.instance().id), '"${aws_instance.id_7.id}"')
 
 # compute on resource
-assert.eq(str(aws.data.ami().id), '"${data.aws_ami.id_8.id}"')
+assert.eq(str(aws.data.ami().id), '"${data.aws_ami.id_8.id}"')
+
+gcp = provider("google", "3.13.0")
+
+# computed on list with MaxItem:1
+cluster = gcp.resource.container_cluster("foo")
+assert.eq(str(cluster.master_auth.client_certificate), '"${google_container_cluster.foo.master_auth.0.client_certificate}"')