command/format: minor adjustments to plan rendering

This change makes various minor adjustments to the rendering of plans
in the output of "terraform plan":

- Resources are identified using the standard resource address syntax,
  rather than exposing the legacy internal representation used in the
  module diff resource keys. This fixes #8713.

- Subjectively, having square brackets in the addresses made it look more
  visually "off" when the same name but with different indices were
  shown together with differing-length "symbols", so the symbols are now
  all padded and right-aligned to three characters for consistent layout
  across all operations.

- The -/+ action is now more visually distinct, using several different
  colors to help communicate what it will do and including a more obvious
  "(new resource required)" marker to help draw attention to this not
  being just an update diff. This fixes #15350.

- The resources are now sorted in a manner that sorts index [10] after
  index [9], rather than after index [1] as we did before. This makes it
  easier to scan the list and avoids the common confusion where it seems
  that there are only 10 items when in fact there are 11-20 items with
  all the tens hiding further up in the list.

command/format/plan.go

@@ -6,6 +6,7 @@ import (
 	"sort"
 	"strings"
 
+	"github.com/hashicorp/terraform/config"
 	"github.com/hashicorp/terraform/terraform"
 	"github.com/mitchellh/colorstring"
 )
@@ -58,18 +59,27 @@ func formatPlanModuleExpand(
 		return
 	}
 
-	var moduleName string
+	var modulePath []string
 	if !m.IsRoot() {
-		moduleName = fmt.Sprintf("module.%s", strings.Join(m.Path[1:], "."))
+		modulePath = m.Path[1:]
 	}
 
 	// We want to output the resources in sorted order to make things
 	// easier to scan through, so get all the resource names and sort them.
 	names := make([]string, 0, len(m.Resources))
-	for name, _ := range m.Resources {
+	addrs := map[string]*terraform.ResourceAddress{}
+	for name := range m.Resources {
 		names = append(names, name)
+		var err error
+		addrs[name], err = terraform.ParseResourceAddressForInstanceDiff(modulePath, name)
+		if err != nil {
+			// should never happen; indicates invalid diff
+			panic("invalid resource address in diff")
+		}
 	}
-	sort.Strings(names)
+	sort.Slice(names, func(i, j int) bool {
+		return addrs[names[i]].Less(addrs[names[j]])
+	})
 
 	// Go through each sorted name and start building the output
 	for _, name := range names {
@@ -78,25 +88,23 @@ func formatPlanModuleExpand(
 			continue
 		}
 
-		dataSource := strings.HasPrefix(name, "data.")
-
-		if moduleName != "" {
-			name = moduleName + "." + name
-		}
+		addr := addrs[name]
+		addrStr := addr.String()
+		dataSource := addr.Mode == config.DataResourceMode
 
 		// Determine the color for the text (green for adding, yellow
 		// for change, red for delete), and symbol, and output the
 		// resource header.
 		color := "yellow"
-		symbol := "~"
+		symbol := "  ~"
 		oldValues := true
 		switch rdiff.ChangeType() {
 		case terraform.DiffDestroyCreate:
-			color = "green"
-			symbol = "-/+"
+			color = "yellow"
+			symbol = "[red]-[reset]/[green]+[reset][yellow]"
 		case terraform.DiffCreate:
 			color = "green"
-			symbol = "+"
+			symbol = "  +"
 			oldValues = false
 
 			// If we're "creating" a data resource then we'll present it
@@ -106,12 +114,12 @@ func formatPlanModuleExpand(
 			// to work with, so we need to cheat and exploit knowledge of the
 			// naming scheme for data resources.
 			if dataSource {
-				symbol = "<="
+				symbol = " <="
 				color = "cyan"
 			}
 		case terraform.DiffDestroy:
 			color = "red"
-			symbol = "-"
+			symbol = "  -"
 		}
 
 		var extraAttr []string
@@ -125,10 +133,13 @@ func formatPlanModuleExpand(
 		if len(extraAttr) > 0 {
 			extraStr = fmt.Sprintf(" (%s)", strings.Join(extraAttr, ", "))
 		}
+		if rdiff.ChangeType() == terraform.DiffDestroyCreate {
+			extraStr = extraStr + opts.Color.Color(" [red][bold](new resource required)")
+		}
 
 		buf.WriteString(opts.Color.Color(fmt.Sprintf(
 			"[%s]%s %s%s\n",
-			color, symbol, name, extraStr)))
+			color, symbol, addrStr, extraStr)))
 
 		// Get all the attributes that are changing, and sort them. Also
 		// determine the longest key so that we can align them all.
@@ -175,7 +186,7 @@ func formatPlanModuleExpand(
 					u = attrDiff.Old
 				}
 				buf.WriteString(fmt.Sprintf(
-					"    %s:%s %#v => %#v%s\n",
+					"      %s:%s %#v => %#v%s\n",
 					attrK,
 					strings.Repeat(" ", keyLen-len(attrK)),
 					u,
@@ -183,7 +194,7 @@ func formatPlanModuleExpand(
 					updateMsg))
 			} else {
 				buf.WriteString(fmt.Sprintf(
-					"    %s:%s %#v%s\n",
+					"      %s:%s %#v%s\n",
 					attrK,
 					strings.Repeat(" ", keyLen-len(attrK)),
 					v,

command/format/plan_test.go

@@ -121,7 +121,7 @@ func TestPlan_rootDataSource(t *testing.T) {
 
 	expected := strings.TrimSpace(`
  <= data.type.name
-    A: "B"
+      A: "B"
 	`)
 	if actual != expected {
 		t.Fatalf("expected:\n\n%s\n\ngot:\n\n%s", expected, actual)
@@ -162,7 +162,7 @@ func TestPlan_nestedDataSource(t *testing.T) {
 
 	expected := strings.TrimSpace(`
  <= module.nested.data.type.name
-    A: "B"
+      A: "B"
 	`)
 	if actual != expected {
 		t.Fatalf("expected:\n\n%s\n\ngot:\n\n%s", expected, actual)