Add the Variable struct

earlydecoder/decoder.go

@@ -5,7 +5,7 @@ import (
 
 	"github.com/hashicorp/go-version"
 	"github.com/hashicorp/hcl/v2"
-	"github.com/hashicorp/terraform-registry-address"
+	tfaddr "github.com/hashicorp/terraform-registry-address"
 	"github.com/hashicorp/terraform-schema/module"
 )
 
@@ -127,10 +127,15 @@ func LoadModule(path string, files map[string]*hcl.File) (*module.Meta, hcl.Diag
 		}
 	}
 
+	variables := make(map[string]module.Variable)
+	for key, variable := range mod.Variables {
+		variables[key] = *variable
+	}
 	return &module.Meta{
 		Path:                 path,
 		ProviderReferences:   refs,
 		ProviderRequirements: providerRequirements,
 		CoreRequirements:     coreRequirements,
+		Variables:            variables,
 	}, diags
 }

earlydecoder/decoder_test.go

@@ -8,25 +8,30 @@ import (
 	"github.com/hashicorp/go-version"
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/hclsyntax"
-	"github.com/hashicorp/terraform-registry-address"
+	tfaddr "github.com/hashicorp/terraform-registry-address"
 	"github.com/hashicorp/terraform-schema/module"
+	"github.com/zclconf/go-cty-debug/ctydebug"
+	"github.com/zclconf/go-cty/cty"
 )
 
+type testCase struct {
+	name         string
+	cfg          string
+	expectedMeta *module.Meta
+}
+
 func TestLoadModule(t *testing.T) {
 	path := t.TempDir()
 
-	testCases := []struct {
-		name         string
-		cfg          string
-		expectedMeta *module.Meta
-	}{
+	testCases := []testCase{
 		{
 			"empty config",
 			``,
 			&module.Meta{
 				Path:                 path,
 				ProviderReferences:   map[module.ProviderRef]tfaddr.Provider{},
 				ProviderRequirements: map[tfaddr.Provider]version.Constraints{},
+				Variables:            map[string]module.Variable{},
 			},
 		},
 		{
@@ -40,6 +45,7 @@ terraform {
 				CoreRequirements:     mustConstraints(t, "~> 0.12"),
 				ProviderReferences:   map[module.ProviderRef]tfaddr.Provider{},
 				ProviderRequirements: map[tfaddr.Provider]version.Constraints{},
+				Variables:            map[string]module.Variable{},
 			},
 		},
 		{
@@ -76,6 +82,7 @@ provider "grafana" {
 					tfaddr.NewLegacyProvider("google"):  {},
 					tfaddr.NewLegacyProvider("grafana"): {},
 				},
+				Variables: map[string]module.Variable{},
 			},
 		},
 		{
@@ -112,6 +119,7 @@ provider "grafana" {
 					tfaddr.NewLegacyProvider("google"):  mustConstraints(t, ">= 3.0.0"),
 					tfaddr.NewLegacyProvider("grafana"): {},
 				},
+				Variables: map[string]module.Variable{},
 			},
 		},
 		{
@@ -152,6 +160,7 @@ provider "grafana" {
 					tfaddr.NewLegacyProvider("google"):  mustConstraints(t, ">= 3.0.0"),
 					tfaddr.NewLegacyProvider("grafana"): {},
 				},
+				Variables: map[string]module.Variable{},
 			},
 		},
 		{
@@ -222,6 +231,7 @@ provider "grafana" {
 						Type:      "grafana",
 					}: mustConstraints(t, "2.1.0"),
 				},
+				Variables: map[string]module.Variable{},
 			},
 		},
 		{
@@ -282,6 +292,7 @@ resource "google_storage_bucket" "bucket" {
 						Type:      "google",
 					}: mustConstraints(t, "2.0.0"),
 				},
+				Variables: map[string]module.Variable{},
 			},
 		},
 		{
@@ -343,6 +354,7 @@ resource "google_storage_bucket" "bucket" {
 						Type:      "google",
 					}: mustConstraints(t, "2.0.0"),
 				},
+				Variables: map[string]module.Variable{},
 			},
 		},
 		{
@@ -396,6 +408,7 @@ provider "aws" {
 						Type:      "google",
 					}: mustConstraints(t, "2.0.0"),
 				},
+				Variables: map[string]module.Variable{},
 			},
 		},
 		{
@@ -455,6 +468,7 @@ provider "aws" {
 						Type:      "google",
 					}: mustConstraints(t, "2.0.0"),
 				},
+				Variables: map[string]module.Variable{},
 			},
 		},
 		{
@@ -489,11 +503,114 @@ resource "google_something" "test" {
 						Type:      "google-beta",
 					}: mustConstraints(t, "2.0.0"),
 				},
+				Variables: map[string]module.Variable{},
 			},
 		},
 	}
 
-	opts := cmp.Comparer(compareVersionConstraint)
+	executeTestCases(testCases, t, path)
+}
+
+func TestLoadModule_Variables(t *testing.T) {
+	path := t.TempDir()
+
+	testCases := []testCase{
+		{
+			"empty variables",
+			`
+variable "name" {
+}`,
+			&module.Meta{
+				Path:                 path,
+				ProviderReferences:   map[module.ProviderRef]tfaddr.Provider{},
+				ProviderRequirements: map[tfaddr.Provider]version.Constraints{},
+				Variables: map[string]module.Variable{
+					"name": {
+						Type: cty.DynamicPseudoType,
+					},
+				},
+			},
+		},
+		{
+			"variables with type",
+			`
+variable "name" {
+	type = string
+}`,
+			&module.Meta{
+				Path:                 path,
+				ProviderReferences:   map[module.ProviderRef]tfaddr.Provider{},
+				ProviderRequirements: map[tfaddr.Provider]version.Constraints{},
+				Variables: map[string]module.Variable{
+					"name": {
+						Type: cty.String,
+					},
+				},
+			},
+		},
+		{
+			"variables with description",
+			`
+variable "name" {
+	description = "description"
+}`,
+			&module.Meta{
+				Path:                 path,
+				ProviderReferences:   map[module.ProviderRef]tfaddr.Provider{},
+				ProviderRequirements: map[tfaddr.Provider]version.Constraints{},
+				Variables: map[string]module.Variable{
+					"name": {
+						Type:        cty.DynamicPseudoType,
+						Description: "description",
+					},
+				},
+			},
+		},
+		{
+			"variables with sensitive",
+			`
+variable "name" {
+	sensitive = true
+}`,
+			&module.Meta{
+				Path:                 path,
+				ProviderReferences:   map[module.ProviderRef]tfaddr.Provider{},
+				ProviderRequirements: map[tfaddr.Provider]version.Constraints{},
+				Variables: map[string]module.Variable{
+					"name": {
+						Type:        cty.DynamicPseudoType,
+						IsSensitive: true,
+					},
+				},
+			},
+		},
+		{
+			"variables with type and description and sensitive",
+			`
+variable "name" {
+	type = string
+	description = "description"
+	sensitive = true
+}`,
+			&module.Meta{
+				Path:                 path,
+				ProviderReferences:   map[module.ProviderRef]tfaddr.Provider{},
+				ProviderRequirements: map[tfaddr.Provider]version.Constraints{},
+				Variables: map[string]module.Variable{
+					"name": {
+						Type:        cty.String,
+						Description: "description",
+						IsSensitive: true,
+					},
+				},
+			},
+		},
+	}
+	executeTestCases(testCases, t, path)
+
+}
+func executeTestCases(testCases []testCase, t *testing.T, path string) {
+	opts := getCustomComparers()
 
 	for i, tc := range testCases {
 		t.Run(fmt.Sprintf("%d-%s", i, tc.name), func(t *testing.T) {
@@ -510,7 +627,7 @@ resource "google_something" "test" {
 				t.Fatal(diags)
 			}
 
-			if diff := cmp.Diff(tc.expectedMeta, meta, opts); diff != "" {
+			if diff := cmp.Diff(tc.expectedMeta, meta, opts...); diff != "" {
 				t.Fatalf("module meta doesn't match: %s", diff)
 			}
 		})
@@ -528,3 +645,10 @@ func mustConstraints(t *testing.T, vc string) version.Constraints {
 func compareVersionConstraint(x, y version.Constraint) bool {
 	return x.String() == y.String()
 }
+
+func getCustomComparers() []cmp.Option {
+	return []cmp.Option{
+		cmp.Comparer(compareVersionConstraint),
+		ctydebug.CmpOptions,
+	}
+}

earlydecoder/load_module.go

@@ -6,7 +6,9 @@ import (
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/gohcl"
 	"github.com/hashicorp/hcl/v2/hclsyntax"
+	"github.com/hashicorp/terraform-schema/internal/typeexpr"
 	"github.com/hashicorp/terraform-schema/module"
+	"github.com/zclconf/go-cty/cty"
 )
 
 // decodedModule is the type representing a decoded Terraform module.
@@ -16,15 +18,17 @@ type decodedModule struct {
 	ProviderConfigs      map[string]*providerConfig
 	Resources            map[string]*resource
 	DataSources          map[string]*dataSource
+	Variables            map[string]*module.Variable
 }
 
 func newDecodedModule() *decodedModule {
 	return &decodedModule{
 		RequiredCore:         make([]string, 0),
-		ProviderRequirements: make(map[string]*providerRequirement, 0),
-		ProviderConfigs:      make(map[string]*providerConfig, 0),
-		Resources:            make(map[string]*resource, 0),
-		DataSources:          make(map[string]*dataSource, 0),
+		ProviderRequirements: make(map[string]*providerRequirement),
+		ProviderConfigs:      make(map[string]*providerConfig),
+		Resources:            make(map[string]*resource),
+		DataSources:          make(map[string]*dataSource),
+		Variables:            make(map[string]*module.Variable),
 	}
 }
 
@@ -166,7 +170,35 @@ func loadModuleFromFile(file *hcl.File, mod *decodedModule) hcl.Diagnostics {
 					LocalName: inferProviderNameFromType(r.Type),
 				}
 			}
+
+		case "variable":
+			content, _, contentDiags := block.Body.PartialContent(variableSchema)
+			diags = append(diags, contentDiags...)
+			name := block.Labels[0]
+			description := ""
+			isSensitive := false
+			var valDiags hcl.Diagnostics
+			if attr, defined := content.Attributes["description"]; defined {
+				valDiags = gohcl.DecodeExpression(attr.Expr, nil, &description)
+				diags = append(diags, valDiags...)
+			}
+			varType := cty.DynamicPseudoType
+			if attr, defined := content.Attributes["type"]; defined {
+				varType, valDiags = typeexpr.TypeConstraint(attr.Expr)
+				diags = append(diags, valDiags...)
+			}
+			if attr, defined := content.Attributes["sensitive"]; defined {
+				valDiags = gohcl.DecodeExpression(attr.Expr, nil, &isSensitive)
+				diags = append(diags, valDiags...)
+			}
+			mod.Variables[name] = &module.Variable{
+				Type:        varType,
+				Description: description,
+				IsSensitive: isSensitive,
+			}
+
 		}
+
 	}
 
 	return diags

earlydecoder/schema.go

@@ -21,6 +21,10 @@ var rootSchema = &hcl.BodySchema{
 			Type:       "data",
 			LabelNames: []string{"type", "name"},
 		},
+		{
+			Type:       "variable",
+			LabelNames: []string{"name"},
+		},
 	},
 }
 
@@ -55,3 +59,20 @@ var resourceSchema = &hcl.BodySchema{
 		},
 	},
 }
+
+var variableSchema = &hcl.BodySchema{
+	Attributes: []hcl.AttributeSchema{
+		{
+			Name: "description",
+		},
+		{
+			Name: "type",
+		},
+		{
+			Name: "sensitive",
+		},
+		{
+			Name: "default",
+		},
+	},
+}

internal/typeexpr/doc.go

@@ -0,0 +1,10 @@
+// Package typeexpr is a fork of github.com/hashicorp/hcl/v2/ext/typeexpr
+// which has additional experimental support for optional attributes.
+//
+// This is here as part of the module_variable_optional_attrs experiment.
+// If that experiment is successful, the changes here may be upstreamed into
+// HCL itself or, if we deem it to be Terraform-specific, we should at least
+// update this documentation to reflect that this is now the primary
+// Terraform-specific type expression implementation, separate from the
+// upstream HCL one.
+package typeexpr