config: merge/append for local values

It seems that this somehow got lost in the commit/rebase shuffle and
wasn't caught by the tests that _did_ make it because they were all using
just one file.

As a result of this bug, locals would fail to work correctly in any
configuration with more than one .tf file.

Along with restoring the append/merge behavior, this also reworks some of
the tests to exercise the multi-file case as better insurance against
regressions of this sort in future.

This fixes #15969.

config/append.go

@@ -82,5 +82,11 @@ func Append(c1, c2 *Config) (*Config, error) {
 		c.Variables = append(c.Variables, c2.Variables...)
 	}
 
+	if len(c1.Locals) > 0 || len(c2.Locals) > 0 {
+		c.Locals = make([]*Local, 0, len(c1.Locals)+len(c2.Locals))
+		c.Locals = append(c.Locals, c1.Locals...)
+		c.Locals = append(c.Locals, c2.Locals...)
+	}
+
 	return c, nil
 }

config/append_test.go

@@ -1,8 +1,11 @@
 package config
 
 import (
+	"fmt"
 	"reflect"
 	"testing"
+
+	"github.com/davecgh/go-spew/spew"
 )
 
 func TestAppend(t *testing.T) {
@@ -30,6 +33,9 @@ func TestAppend(t *testing.T) {
 				Variables: []*Variable{
 					&Variable{Name: "foo"},
 				},
+				Locals: []*Local{
+					&Local{Name: "foo"},
+				},
 
 				unknownKeys: []string{"foo"},
 			},
@@ -53,6 +59,9 @@ func TestAppend(t *testing.T) {
 				Variables: []*Variable{
 					&Variable{Name: "bar"},
 				},
+				Locals: []*Local{
+					&Local{Name: "bar"},
+				},
 
 				unknownKeys: []string{"bar"},
 			},
@@ -81,6 +90,10 @@ func TestAppend(t *testing.T) {
 					&Variable{Name: "foo"},
 					&Variable{Name: "bar"},
 				},
+				Locals: []*Local{
+					&Local{Name: "foo"},
+					&Local{Name: "bar"},
+				},
 
 				unknownKeys: []string{"foo", "bar"},
 			},
@@ -146,13 +159,15 @@ func TestAppend(t *testing.T) {
 	}
 
 	for i, tc := range cases {
+		t.Run(fmt.Sprintf("%02d", i), func(t *testing.T) {
 			actual, err := Append(tc.c1, tc.c2)
 			if err != nil != tc.err {
-			t.Fatalf("%d: error fail", i)
+				t.Errorf("unexpected error: %s", err)
 			}
 
 			if !reflect.DeepEqual(actual, tc.result) {
-			t.Fatalf("%d: bad:\n\n%#v", i, actual)
+				t.Errorf("wrong result\ngot: %swant: %s", spew.Sdump(actual), spew.Sdump(tc.result))
-		}
+			}
+		})
 	}
 }

config/config_test.go

@@ -653,6 +653,22 @@ func TestNameRegexp(t *testing.T) {
 	}
 }
 
+func TestConfigValidate_localValuesMultiFile(t *testing.T) {
+	c, err := LoadDir(filepath.Join(fixtureDir, "validate-local-multi-file"))
+	if err != nil {
+		t.Fatalf("unexpected error during load: %s", err)
+	}
+	if err := c.Validate(); err != nil {
+		t.Fatalf("unexpected error from validate: %s", err)
+	}
+	if len(c.Locals) != 1 {
+		t.Fatalf("got 0 locals; want 1")
+	}
+	if got, want := c.Locals[0].Name, "test"; got != want {
+		t.Errorf("wrong local name\ngot:  %#v\nwant: %#v", got, want)
+	}
+}
+
 func TestProviderConfigName(t *testing.T) {
 	pcs := []*ProviderConfig{
 		&ProviderConfig{Name: "aw"},

config/merge.go

@@ -137,6 +137,21 @@ func Merge(c1, c2 *Config) (*Config, error) {
 		}
 	}
 
+	// Local Values
+	// These are simpler than the other config elements because they are just
+	// flat values and so no deep merging is required.
+	if localsCount := len(c1.Locals) + len(c2.Locals); localsCount != 0 {
+		// Explicit length check above because we want c.Locals to remain
+		// nil if the result would be empty.
+		c.Locals = make([]*Local, 0, len(c1.Locals)+len(c2.Locals))
+		for _, v := range c1.Locals {
+			c.Locals = append(c.Locals, v)
+		}
+		for _, v := range c2.Locals {
+			c.Locals = append(c.Locals, v)
+		}
+	}
+
 	return c, nil
 }
 

config/merge_test.go

@@ -1,8 +1,11 @@
 package config
 
 import (
+	"fmt"
 	"reflect"
 	"testing"
+
+	"github.com/davecgh/go-spew/spew"
 )
 
 func TestMerge(t *testing.T) {
@@ -31,6 +34,9 @@ func TestMerge(t *testing.T) {
 				Variables: []*Variable{
 					&Variable{Name: "foo"},
 				},
+				Locals: []*Local{
+					&Local{Name: "foo"},
+				},
 
 				unknownKeys: []string{"foo"},
 			},
@@ -54,6 +60,9 @@ func TestMerge(t *testing.T) {
 				Variables: []*Variable{
 					&Variable{Name: "bar"},
 				},
+				Locals: []*Local{
+					&Local{Name: "bar"},
+				},
 
 				unknownKeys: []string{"bar"},
 			},
@@ -82,6 +91,10 @@ func TestMerge(t *testing.T) {
 					&Variable{Name: "foo"},
 					&Variable{Name: "bar"},
 				},
+				Locals: []*Local{
+					&Local{Name: "foo"},
+					&Local{Name: "bar"},
+				},
 
 				unknownKeys: []string{"foo", "bar"},
 			},
@@ -107,6 +120,9 @@ func TestMerge(t *testing.T) {
 					&Variable{Name: "foo", Default: "foo"},
 					&Variable{Name: "foo"},
 				},
+				Locals: []*Local{
+					&Local{Name: "foo"},
+				},
 
 				unknownKeys: []string{"foo"},
 			},
@@ -125,6 +141,9 @@ func TestMerge(t *testing.T) {
 					&Variable{Name: "foo", Default: "bar"},
 					&Variable{Name: "bar"},
 				},
+				Locals: []*Local{
+					&Local{Name: "foo"},
+				},
 
 				unknownKeys: []string{"bar"},
 			},
@@ -147,6 +166,10 @@ func TestMerge(t *testing.T) {
 					&Variable{Name: "foo"},
 					&Variable{Name: "bar"},
 				},
+				Locals: []*Local{
+					&Local{Name: "foo"},
+					&Local{Name: "foo"},
+				},
 
 				unknownKeys: []string{"foo", "bar"},
 			},
@@ -462,13 +485,15 @@ func TestMerge(t *testing.T) {
 	}
 
 	for i, tc := range cases {
+		t.Run(fmt.Sprintf("%02d", i), func(t *testing.T) {
 			actual, err := Merge(tc.c1, tc.c2)
 			if err != nil != tc.err {
-			t.Fatalf("%d: error fail", i)
+				t.Errorf("unexpected error: %s", err)
 			}
 
 			if !reflect.DeepEqual(actual, tc.result) {
-			t.Fatalf("%d: bad:\n\n%#v", i, actual)
+				t.Errorf("wrong result\ngot: %swant: %s", spew.Sdump(actual), spew.Sdump(tc.result))
-		}
+			}
+		})
 	}
 }

config/test-fixtures/validate-local-multi-file/local-def.tf

@@ -0,0 +1,4 @@
+
+locals {
+  test = "${upper("hello, world")}"
+}

config/test-fixtures/validate-local-multi-file/local-use.tf

@@ -0,0 +1,8 @@
+
+resource "test_resource" "foo" {
+  value = "${local.test}"
+}
+
+output "test" {
+  value = "${local.test}"
+}

terraform/test-fixtures/apply-local-val/main.tf

@@ -8,11 +8,3 @@ locals {
   result_2 = "${local.result_1}"
   result_3 = "${local.result_2} world"
 }
-
-output "result_1" {
-  value = "${local.result_1}"
-}
-
-output "result_3" {
-  value = "${local.result_3}"
-}

terraform/test-fixtures/apply-local-val/outputs.tf

@@ -0,0 +1,9 @@
+# These are in a separate file to make sure config merging is working properly
+
+output "result_1" {
+  value = "${local.result_1}"
+}
+
+output "result_3" {
+  value = "${local.result_3}"
+}