read+write the new dependencies in the statefile

The test fixture did not like having modules when using the generic json
map, so read and compare the states in the final *File datastructure.

states/instance_object_src.go

@@ -88,6 +88,7 @@ func (os *ResourceInstanceObjectSrc) Decode(ty cty.Type) (*ResourceInstanceObjec
 		Value:        val,
 		Status:       os.Status,
 		Dependencies: os.Dependencies,
+		DependsOn:    os.DependsOn,
 		Private:      os.Private,
 	}, nil
 }

states/state_deepcopy.go

@@ -172,6 +172,7 @@ func (obj *ResourceInstanceObjectSrc) DeepCopy() *ResourceInstanceObjectSrc {
 		AttrsFlat:     attrsFlat,
 		AttrsJSON:     attrsJSON,
 		Dependencies:  dependencies,
+		DependsOn:     dependsOn,
 	}
 }
 

states/statefile/roundtrip_test.go

@@ -2,7 +2,6 @@ package statefile
 
 import (
 	"bytes"
-	"encoding/json"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -11,8 +10,6 @@ import (
 	"testing"
 
 	"github.com/go-test/deep"
-
-	tfversion "github.com/hashicorp/terraform/version"
 )
 
 func TestRoundtrip(t *testing.T) {
@@ -22,8 +19,6 @@ func TestRoundtrip(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	currentVersion := tfversion.Version
-
 	for _, info := range entries {
 		const inSuffix = ".in.tfstate"
 		const outSuffix = ".out.tfstate"
@@ -39,14 +34,20 @@ func TestRoundtrip(t *testing.T) {
 		outName := name + outSuffix
 
 		t.Run(name, func(t *testing.T) {
-			ir, err := os.Open(filepath.Join(dir, inName))
-			if err != nil {
-				t.Fatal(err)
-			}
 			oSrcWant, err := ioutil.ReadFile(filepath.Join(dir, outName))
 			if err != nil {
 				t.Fatal(err)
 			}
+			oWant, diags := readStateV4(oSrcWant)
+			if diags.HasErrors() {
+				t.Fatal(diags.Err())
+			}
+
+			ir, err := os.Open(filepath.Join(dir, inName))
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer ir.Close()
 
 			f, err := Read(ir)
 			if err != nil {
@@ -58,20 +59,12 @@ func TestRoundtrip(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
-			oSrcGot := buf.Bytes()
+			oSrcWritten := buf.Bytes()
 
-			var oGot, oWant map[string]interface{}
+			oGot, diags := readStateV4(oSrcWritten)
-			err = json.Unmarshal(oSrcGot, &oGot)
+			if diags.HasErrors() {
-			if err != nil {
+				t.Fatal(diags.Err())
-				t.Fatalf("result isn't JSON: %s", err)
 			}
-			err = json.Unmarshal(oSrcWant, &oWant)
-			if err != nil {
-				t.Fatalf("wanted result isn't JSON: %s", err)
-			}
-
-			// A newly written state should always reflect the current terraform version.
-			oWant["terraform_version"] = currentVersion
 
 			problems := deep.Equal(oGot, oWant)
 			sort.Strings(problems)

states/statefile/testdata/roundtrip/v4-foreach.in.tfstate

@@ -0,0 +1,36 @@
+{
+  "version": 4,
+  "serial": 0,
+  "lineage": "f2968801-fa14-41ab-a044-224f3a4adf04",
+  "terraform_version": "0.12.0",
+  "outputs": {
+    "numbers": {
+      "type": "string",
+      "value": "0,1"
+    }
+  },
+  "resources": [
+    {
+      "module": "module.modA",
+      "mode": "managed",
+      "type": "null_resource",
+      "name": "resource",
+      "provider": "provider.null",
+      "instances": [
+        {
+          "schema_version": 0,
+          "attributes": {
+            "id": "4639265839606265182",
+            "triggers": {
+              "input": "test"
+            }
+          },
+          "private": "bnVsbA==",
+          "depends_on": [
+            "var.input"
+          ]
+        }
+      ]
+    }
+  ]
+}

states/statefile/testdata/roundtrip/v4-foreach.out.tfstate

@@ -0,0 +1 @@
+v4-foreach.in.tfstate

states/statefile/testdata/roundtrip/v4-modules.in.tfstate

@@ -0,0 +1,88 @@
+{
+  "version": 4,
+  "terraform_version": "0.12.0",
+  "serial": 0,
+  "lineage": "f2968801-fa14-41ab-a044-224f3a4adf04",
+  "outputs": {
+    "numbers": {
+      "value": "0,1",
+      "type": "string"
+    }
+  },
+  "resources": [
+    {
+      "mode": "managed",
+      "type": "null_resource",
+      "name": "bar",
+      "provider": "provider.null",
+      "instances": [
+        {
+          "schema_version": 0,
+          "attributes_flat": {
+            "id": "5388490630832483079",
+            "triggers.%": "1",
+            "triggers.whaaat": "0,1"
+          },
+          "depends_on": [
+            "null_resource.foo"
+          ]
+        }
+      ]
+    },
+    {
+      "module": "module.modB",
+      "mode": "managed",
+      "type": "null_resource",
+      "name": "bar",
+      "each": "map",
+      "provider": "provider.null",
+      "instances": [
+        {
+          "index_key": "a",
+          "schema_version": 0,
+          "attributes_flat": {
+            "id": "8212585058302700791"
+          },
+          "dependencies": [
+            "module.modA.null_resource.resource"
+          ]
+        },
+        {
+          "index_key": "b",
+          "schema_version": 0,
+          "attributes_flat": {
+            "id": "1523897709610803586"
+          },
+          "dependencies": [
+            "module.modA.null_resource.resource"
+          ]
+        }
+      ]
+    },
+    {
+      "module": "module.modA",
+      "mode": "managed",
+      "type": "null_resource",
+      "name": "resource",
+      "provider": "provider.null",
+      "instances": [
+        {
+          "schema_version": 0,
+          "attributes": {
+            "id": "4639265839606265182",
+            "triggers": {
+              "input": "test"
+            }
+          },
+          "private": "bnVsbA==",
+          "dependencies": [
+            "null_resource.bar"
+          ],
+          "depends_on": [
+            "var.input"
+          ]
+        }
+      ]
+    }
+  ]
+}

states/statefile/testdata/roundtrip/v4-modules.out.tfstate

@@ -0,0 +1 @@
+v4-modules.in.tfstate

states/statefile/version3_upgrade.go

@@ -313,7 +313,7 @@ func upgradeInstanceObjectV3ToV4(rsOld *resourceStateV2, isOld *instanceStateV2,
 		Status:         status,
 		Deposed:        string(deposedKey),
 		AttributesFlat: attributes,
-		Dependencies:   dependencies,
+		DependsOn:      dependencies,
 		SchemaVersion:  schemaVersion,
 		PrivateRaw:     privateJSON,
 	}, nil

states/statefile/version4.go

@@ -181,7 +181,10 @@ func prepareStateV4(sV4 *stateV4) (*File, tfdiags.Diagnostics) {
 			}
 
 			{
-				depsRaw := isV4.Dependencies
+				// Allow both the deprecated `depends_on` and new
+				// `dependencies` to coexist for now so resources can be
+				// upgraded as they are refreshed.
+				depsRaw := isV4.DependsOn
 				deps := make([]addrs.Referenceable, 0, len(depsRaw))
 				for _, depRaw := range depsRaw {
 					ref, refDiags := addrs.ParseRefStr(depRaw)
@@ -202,6 +205,20 @@ func prepareStateV4(sV4 *stateV4) (*File, tfdiags.Diagnostics) {
 					}
 					deps = append(deps, ref.Subject)
 				}
+				obj.DependsOn = deps
+			}
+
+			{
+				depsRaw := isV4.Dependencies
+				deps := make([]addrs.AbsResource, 0, len(depsRaw))
+				for _, depRaw := range depsRaw {
+					addr, addrDiags := addrs.ParseAbsResourceStr(depRaw)
+					diags = diags.Append(addrDiags)
+					if addrDiags.HasErrors() {
+						continue
+					}
+					deps = append(deps, addr)
+				}
 				obj.Dependencies = deps
 			}
 
@@ -466,6 +483,11 @@ func appendInstanceObjectStateV4(rs *states.Resource, is *states.ResourceInstanc
 		deps[i] = depAddr.String()
 	}
 
+	depOn := make([]string, len(obj.DependsOn))
+	for i, depAddr := range obj.DependsOn {
+		depOn[i] = depAddr.String()
+	}
+
 	var rawKey interface{}
 	switch tk := key.(type) {
 	case addrs.IntKey:
@@ -491,6 +513,7 @@ func appendInstanceObjectStateV4(rs *states.Resource, is *states.ResourceInstanc
 		AttributesRaw:  obj.AttrsJSON,
 		PrivateRaw:     privateRaw,
 		Dependencies:   deps,
+		DependsOn:      depOn,
 	}), diags
 }
 
@@ -540,7 +563,8 @@ type instanceObjectStateV4 struct {
 
 	PrivateRaw []byte `json:"private,omitempty"`
 
-	Dependencies []string `json:"depends_on,omitempty"`
+	Dependencies []string `json:"dependencies,omitempty"`
+	DependsOn    []string `json:"depends_on,omitempty"`
 }
 
 // stateVersionV4 is a weird special type we use to produce our hard-coded