command: Add vars to providers command

internal/command/arguments/providers.go

@@ -9,6 +9,9 @@ import "github.com/hashicorp/terraform/internal/tfdiags"
 type Providers struct {
 	// TestsDirectory is the directory containing Terraform test files.
 	TestsDirectory string
+
+	// Vars are the variable-related flags (-var, -var-file).
+	Vars *Vars
 }
 
 // ParseProviders processes CLI arguments, returning a Providers value and
@@ -16,9 +19,11 @@ type Providers struct {
 // representing the best effort interpretation of the arguments.
 func ParseProviders(args []string) (*Providers, tfdiags.Diagnostics) {
 	var diags tfdiags.Diagnostics
-	providers := &Providers{}
+	providers := &Providers{
+		Vars: &Vars{},
+	}
 
-	cmdFlags := defaultFlagSet("providers")
+	cmdFlags := extendedFlagSet("providers", nil, nil, providers.Vars)
 	cmdFlags.StringVar(&providers.TestsDirectory, "test-directory", "tests", "test-directory")
 
 	if err := cmdFlags.Parse(args); err != nil {

internal/command/arguments/providers_test.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
 	"github.com/hashicorp/terraform/internal/tfdiags"
 )
 
@@ -19,23 +20,27 @@ func TestParseProviders_valid(t *testing.T) {
 			nil,
 			&Providers{
 				TestsDirectory: "tests",
+				Vars:           &Vars{},
 			},
 		},
 		"test directory": {
 			[]string{"-test-directory=integration-tests"},
 			&Providers{
 				TestsDirectory: "integration-tests",
+				Vars:           &Vars{},
 			},
 		},
 	}
 
+	cmpOpts := cmpopts.IgnoreUnexported(Vars{})
+
 	for name, tc := range testCases {
 		t.Run(name, func(t *testing.T) {
 			got, diags := ParseProviders(tc.args)
 			if len(diags) > 0 {
 				t.Fatalf("unexpected diags: %v", diags)
 			}
-			if diff := cmp.Diff(tc.want, got); diff != "" {
+			if diff := cmp.Diff(tc.want, got, cmpOpts); diff != "" {
 				t.Fatalf("unexpected result\n%s", diff)
 			}
 		})
@@ -52,6 +57,7 @@ func TestParseProviders_invalid(t *testing.T) {
 			[]string{"-wat"},
 			&Providers{
 				TestsDirectory: "tests",
+				Vars:           &Vars{},
 			},
 			tfdiags.Diagnostics{
 				tfdiags.Sourceless(
@@ -65,6 +71,7 @@ func TestParseProviders_invalid(t *testing.T) {
 			[]string{"foo"},
 			&Providers{
 				TestsDirectory: "tests",
+				Vars:           &Vars{},
 			},
 			tfdiags.Diagnostics{
 				tfdiags.Sourceless(
@@ -76,13 +83,59 @@ func TestParseProviders_invalid(t *testing.T) {
 		},
 	}
 
+	cmpOpts := cmpopts.IgnoreUnexported(Vars{})
+
 	for name, tc := range testCases {
 		t.Run(name, func(t *testing.T) {
 			got, gotDiags := ParseProviders(tc.args)
-			if diff := cmp.Diff(tc.want, got); diff != "" {
+			if diff := cmp.Diff(tc.want, got, cmpOpts); diff != "" {
 				t.Fatalf("unexpected result\n%s", diff)
 			}
 			tfdiags.AssertDiagnosticsMatch(t, gotDiags, tc.wantDiags)
 		})
 	}
 }
+
+func TestParseProviders_vars(t *testing.T) {
+	testCases := map[string]struct {
+		args []string
+		want []FlagNameValue
+	}{
+		"var": {
+			args: []string{"-var", "foo=bar"},
+			want: []FlagNameValue{
+				{Name: "-var", Value: "foo=bar"},
+			},
+		},
+		"var-file": {
+			args: []string{"-var-file", "cool.tfvars"},
+			want: []FlagNameValue{
+				{Name: "-var-file", Value: "cool.tfvars"},
+			},
+		},
+		"both": {
+			args: []string{
+				"-var", "foo=bar",
+				"-var-file", "cool.tfvars",
+				"-var", "boop=beep",
+			},
+			want: []FlagNameValue{
+				{Name: "-var", Value: "foo=bar"},
+				{Name: "-var-file", Value: "cool.tfvars"},
+				{Name: "-var", Value: "boop=beep"},
+			},
+		},
+	}
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			got, diags := ParseProviders(tc.args)
+			if len(diags) > 0 {
+				t.Fatalf("unexpected diags: %v", diags)
+			}
+			if vars := got.Vars.All(); !cmp.Equal(vars, tc.want) {
+				t.Fatalf("unexpected vars: %#v", vars)
+			}
+		})
+	}
+}

internal/command/providers.go

@@ -43,6 +43,23 @@ func (c *ProvidersCommand) Run(args []string) int {
 		return 1
 	}
 
+	loader, err := c.initConfigLoader()
+	if err != nil {
+		diags = diags.Append(err)
+		c.showDiagnostics(diags)
+		return 1
+	}
+
+	var varDiags tfdiags.Diagnostics
+	c.VariableValues, varDiags = parsedArgs.Vars.CollectValues(func(filename string, src []byte) {
+		loader.Parser().ForceFileSource(filename, src)
+	})
+	diags = diags.Append(varDiags)
+	if diags.HasErrors() {
+		c.showDiagnostics(diags)
+		return 1
+	}
+
 	empty, err := configs.IsEmptyDir(configPath, parsedArgs.TestsDirectory)
 	if err != nil {
 		diags = diags.Append(tfdiags.Sourceless(
@@ -178,5 +195,14 @@ Usage: terraform [global options] providers [options] [DIR]
 
 Options:
 
-  -test-directory=path	Set the Terraform test directory, defaults to "tests".
+  -test-directory=path  Set the Terraform test directory, defaults to "tests".
+
+  -var 'foo=bar'        Set a value for one of the input variables in the root
+                        module of the configuration. Use this option more than
+                        once to set more than one variable.
+
+  -var-file=filename    Load variable values from the given file, in addition
+                        to the default files terraform.tfvars and *.auto.tfvars.
+                        Use this option more than once to include more than one
+                        variables file.
 `