terraform show -json: Add Errored field to output for plan

internal/command/jsonplan/plan.go

@@ -63,6 +63,7 @@ type plan struct {
 	RelevantAttributes []ResourceAttr    `json:"relevant_attributes,omitempty"`
 	Checks             json.RawMessage   `json:"checks,omitempty"`
 	Timestamp          string            `json:"timestamp,omitempty"`
+	Errored            bool              `json:"errored"`
 }
 
 func newPlan() *plan {
@@ -221,6 +222,7 @@ func Marshal(
 	output := newPlan()
 	output.TerraformVersion = version.String()
 	output.Timestamp = p.Timestamp.Format(time.RFC3339)
+	output.Errored = p.Errored
 
 	err := output.marshalPlanVariables(p.VariableValues, config.Module.Variables)
 	if err != nil {

internal/command/show_test.go

@@ -421,7 +421,43 @@ func TestShow_planWithForceReplaceChange(t *testing.T) {
 	if !strings.Contains(got, want) {
 		t.Fatalf("unexpected output\ngot: %s\nwant: %s", got, want)
 	}
+}
+
+func TestShow_planErrored(t *testing.T) {
+	_, snap := testModuleWithSnapshot(t, "show")
+	plan := testPlan(t)
+	plan.Errored = true
+	planFilePath := testPlanFile(
+		t,
+		snap,
+		states.NewState(),
+		plan,
+	)
+
+	view, done := testView(t)
+	c := &ShowCommand{
+		Meta: Meta{
+			testingOverrides: metaOverridesForProvider(showFixtureProvider()),
+			View:             view,
+		},
+	}
 
+	args := []string{
+		planFilePath,
+		"-no-color",
+	}
+	code := c.Run(args)
+	output := done(t)
+
+	if code != 0 {
+		t.Fatalf("unexpected exit status %d; want 0\ngot: %s", code, output.Stderr())
+	}
+
+	got := output.Stdout()
+	want := `Planning failed. Terraform encountered an error while generating this plan.`
+	if !strings.Contains(got, want) {
+		t.Fatalf("unexpected output\ngot: %s\nwant: %s", got, want)
+	}
 }
 
 func TestShow_plan_json(t *testing.T) {
@@ -525,6 +561,20 @@ func TestShow_json_output(t *testing.T) {
 				t.Fatalf("init failed\n%s", ui.ErrorWriter)
 			}
 
+			// read expected output
+			wantFile, err := os.Open("output.json")
+			if err != nil {
+				t.Fatalf("unexpected err: %s", err)
+			}
+			defer wantFile.Close()
+			byteValue, err := ioutil.ReadAll(wantFile)
+			if err != nil {
+				t.Fatalf("unexpected err: %s", err)
+			}
+
+			var want plan
+			json.Unmarshal([]byte(byteValue), &want)
+
 			// plan
 			planView, planDone := testView(t)
 			pc := &PlanCommand{
@@ -542,8 +592,15 @@ func TestShow_json_output(t *testing.T) {
 			code := pc.Run(args)
 			planOutput := planDone(t)
 
-			if code != 0 {
-				t.Fatalf("unexpected exit status %d; want 0\ngot: %s", code, planOutput.Stderr())
+			var wantedCode int
+			if want.Errored {
+				wantedCode = 1
+			} else {
+				wantedCode = 0
+			}
+
+			if code != wantedCode {
+				t.Fatalf("unexpected exit status %d; want %d\ngot: %s", code, wantedCode, planOutput.Stderr())
 			}
 
 			// show
@@ -569,22 +626,11 @@ func TestShow_json_output(t *testing.T) {
 			}
 
 			// compare view output to wanted output
-			var got, want plan
+			var got plan
 
 			gotString := showOutput.Stdout()
 			json.Unmarshal([]byte(gotString), &got)
 
-			wantFile, err := os.Open("output.json")
-			if err != nil {
-				t.Fatalf("unexpected err: %s", err)
-			}
-			defer wantFile.Close()
-			byteValue, err := ioutil.ReadAll(wantFile)
-			if err != nil {
-				t.Fatalf("unexpected err: %s", err)
-			}
-			json.Unmarshal([]byte(byteValue), &want)
-
 			// Disregard format version to reduce needless test fixture churn
 			want.FormatVersion = got.FormatVersion
 
@@ -1150,6 +1196,7 @@ type plan struct {
 	OutputChanges   map[string]interface{} `json:"output_changes,omitempty"`
 	PriorState      priorState             `json:"prior_state,omitempty"`
 	Config          map[string]interface{} `json:"configuration,omitempty"`
+	Errored         bool                   `json:"errored"`
 }
 
 type priorState struct {

internal/command/testdata/show-json/plan-error/main.tf

@@ -0,0 +1,15 @@
+locals {
+  ami = "bar"
+}
+
+resource "test_instance" "test" {
+  ami = local.ami
+
+  lifecycle {
+    precondition {
+      // failing condition
+      condition = local.ami != "bar"
+      error_message = "ami is bar"
+    }
+  }
+}

internal/command/testdata/show-json/plan-error/output.json

@@ -0,0 +1,35 @@
+{
+    "format_version": "1.2",
+    "planned_values": {
+        "root_module": {}
+    },
+    "prior_state": {},
+    "configuration": {
+        "provider_config": {
+            "test": {
+                "full_name": "registry.terraform.io/hashicorp/test",
+                "name": "test"
+            }
+        },
+        "root_module": {
+            "resources": [
+                {
+                    "address": "test_instance.test",
+                    "expressions": {
+                        "ami": {
+                            "references": [
+                                "local.ami"
+                            ]
+                        }
+                    },
+                    "mode": "managed",
+                    "name": "test",
+                    "provider_config_key": "test",
+                    "schema_version": 0,
+                    "type": "test_instance"
+                }
+            ]
+        }
+    },
+    "errored": true
+}

website/docs/internals/json-format.mdx

@@ -229,7 +229,11 @@ For ease of consumption by callers, the plan representation includes a partial r
   // resources with postconditions, with as much information as Terraform can
   // recognize at plan time. Some objects will have status "unknown" to
   // indicate that their status will only be determined after applying the plan.
-  "checks" <checks-representation>
+  "checks" <checks-representation>,
+
+  // "errored" indicates whether planning failed. An errored plan cannot be applied,
+  // but the actions planned before failure may help to understand the error.
+  "errored": false
 }
 ```