terraform: test that data sources can reference other data sources

terraform/context_refresh_test.go

@@ -640,6 +640,43 @@ func TestContext2Refresh_dataState(t *testing.T) {
 	}
 }
 
+func TestContext2Refresh_dataStateRefData(t *testing.T) {
+	p := testProvider("null")
+	m := testModule(t, "refresh-data-ref-data")
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: rootModulePath,
+				// Intentionally no resources since data resources are
+				// supposed to refresh themselves even if they didn't
+				// already exist.
+				Resources: map[string]*ResourceState{},
+			},
+		},
+	}
+	ctx := testContext2(t, &ContextOpts{
+		Module: m,
+		Providers: map[string]ResourceProviderFactory{
+			"null": testProviderFuncFixed(p),
+		},
+		State: state,
+	})
+
+	p.ReadDataDiffFn = testDataDiffFn
+	p.ReadDataApplyFn = testDataApplyFn
+
+	s, err := ctx.Refresh()
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	actual := strings.TrimSpace(s.String())
+	expected := strings.TrimSpace(testTerraformRefreshDataRefDataStr)
+	if actual != expected {
+		t.Fatalf("bad:\n\n%s\n\n%s", actual, expected)
+	}
+}
+
 func TestContext2Refresh_tainted(t *testing.T) {
 	p := testProvider("aws")
 	m := testModule(t, "refresh-basic")

terraform/context_test.go

@@ -79,6 +79,18 @@ func testContext2(t *testing.T, opts *ContextOpts) *Context {
 	return ctx
 }
 
+func testDataApplyFn(
+	info *InstanceInfo,
+	d *InstanceDiff) (*InstanceState, error) {
+	return testApplyFn(info, new(InstanceState), d)
+}
+
+func testDataDiffFn(
+	info *InstanceInfo,
+	c *ResourceConfig) (*InstanceDiff, error) {
+	return testDiffFn(info, new(InstanceState), c)
+}
+
 func testApplyFn(
 	info *InstanceInfo,
 	s *InstanceState,

terraform/terraform_test.go

@@ -1492,3 +1492,17 @@ hcl_instance.hcltest:
   foo.1 = b
   type = hcl_instance
 `
+
+const testTerraformRefreshDataRefDataStr = `
+data.null_data_source.bar:
+  ID = foo
+  bar = yes
+  type = null_data_source
+
+  Dependencies:
+    data.null_data_source.foo
+data.null_data_source.foo:
+  ID = foo
+  foo = yes
+  type = null_data_source
+`

terraform/test-fixtures/refresh-data-ref-data/main.tf

@@ -0,0 +1,7 @@
+data "null_data_source" "foo" {
+  foo = "yes"
+}
+
+data "null_data_source" "bar" {
+  bar = "${data.null_data_source.foo.foo}"
+}