Add terraform version command (hashicorp#1016)

This commit adds a new `module.terraform` command which returns the required and discovered version of Terraform in the current workspace.

docs/commands.md

@@ -183,3 +183,25 @@ installed version.
   }
 }
 ```
+
+### `module.terraform`
+
+Provides information about the terraform binary version for the current module.
+
+**Arguments:**
+
+ - `uri` - URI of the directory of the module in question, e.g. `file:///path/to/network`
+
+**Outputs:**
+
+ - `v` - describes version of the format; Will be used in the future to communicate format changes.
+ - `required_version` - Version constraint specified in configuration
+ - `discovered_version` - Version discovered from `terraform version --json` in the directory specified in `uri`
+
+```json
+{
+  "v": 0,
+  "required_version": "~> 0.15",
+  "discovered_version": "1.1.0"
+}
+```

internal/langserver/handlers/command/terraform.go

@@ -0,0 +1,62 @@
+package command
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/creachadair/jrpc2/code"
+	"github.com/hashicorp/terraform-ls/internal/langserver/cmd"
+	"github.com/hashicorp/terraform-ls/internal/langserver/progress"
+	"github.com/hashicorp/terraform-ls/internal/uri"
+)
+
+const terraformVersionRequestVersion = 0
+
+type terraformInfoResponse struct {
+	FormatVersion     int    `json:"v"`
+	RequiredVersion   string `json:"required_version,omitempty"`
+	DiscoveredVersion string `json:"discovered_version,omitempty"`
+}
+
+func (h *CmdHandler) TerraformVersionRequestHandler(ctx context.Context, args cmd.CommandArgs) (interface{}, error) {
+	progress.Begin(ctx, "Initializing")
+	defer func() {
+		progress.End(ctx, "Finished")
+	}()
+
+	response := terraformInfoResponse{
+		FormatVersion: terraformVersionRequestVersion,
+	}
+
+	progress.Report(ctx, "Finding current module info ...")
+	modUri, ok := args.GetString("uri")
+	if !ok || modUri == "" {
+		return response, fmt.Errorf("%w: expected module uri argument to be set", code.InvalidParams.Err())
+	}
+
+	if !uri.IsURIValid(modUri) {
+		return response, fmt.Errorf("URI %q is not valid", modUri)
+	}
+
+	modPath, err := uri.PathFromURI(modUri)
+	if err != nil {
+		return response, err
+	}
+
+	mod, _ := h.StateStore.Modules.ModuleByPath(modPath)
+	if mod == nil {
+		return response, nil
+	}
+
+	progress.Report(ctx, "Recording terraform version info ...")
+	if mod.TerraformVersion != nil {
+		response.DiscoveredVersion = mod.TerraformVersion.String()
+	}
+	if mod.Meta.CoreRequirements != nil {
+		response.RequiredVersion = mod.Meta.CoreRequirements.String()
+	}
+
+	progress.Report(ctx, "Sending response ...")
+
+	return response, nil
+}

internal/langserver/handlers/execute_command.go

@@ -24,6 +24,7 @@ func cmdHandlers(svc *service) cmd.Handlers {
 		cmd.Name("terraform.validate"): cmdHandler.TerraformValidateHandler,
 		cmd.Name("module.calls"):       cmdHandler.ModuleCallsHandler,
 		cmd.Name("module.providers"):   cmdHandler.ModuleProvidersHandler,
+		cmd.Name("module.terraform"):   cmdHandler.TerraformVersionRequestHandler,
 	}
 }
 

internal/langserver/handlers/execute_command_terraform_version_test.go

@@ -0,0 +1,95 @@
+package handlers
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/hashicorp/go-version"
+	"github.com/hashicorp/terraform-ls/internal/document"
+	"github.com/hashicorp/terraform-ls/internal/langserver"
+	"github.com/hashicorp/terraform-ls/internal/langserver/cmd"
+	"github.com/hashicorp/terraform-ls/internal/state"
+	"github.com/hashicorp/terraform-ls/internal/terraform/exec"
+	"github.com/hashicorp/terraform-ls/internal/uri"
+	"github.com/hashicorp/terraform-ls/internal/walker"
+	tfaddr "github.com/hashicorp/terraform-registry-address"
+	tfmod "github.com/hashicorp/terraform-schema/module"
+	"github.com/stretchr/testify/mock"
+)
+
+func TestLangServer_workspaceExecuteCommand_terraformVersion_basic(t *testing.T) {
+	modDir := t.TempDir()
+	modUri := uri.FromPath(modDir)
+
+	s, err := state.NewStateStore()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = s.Modules.Add(modDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	metadata := &tfmod.Meta{
+		Path:             modDir,
+		CoreRequirements: testConstraint(t, "~> 0.15"),
+	}
+
+	err = s.Modules.UpdateMetadata(modDir, metadata, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ver, err := version.NewVersion("1.1.0")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = s.Modules.UpdateTerraformVersion(modDir, ver, map[tfaddr.Provider]*version.Version{}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	wc := walker.NewWalkerCollector()
+
+	ls := langserver.NewLangServerMock(t, NewMockSession(&MockSessionInput{
+		TerraformCalls: &exec.TerraformMockCalls{
+			PerWorkDir: map[string][]*mock.Call{
+				modDir: validTfMockCalls(),
+			},
+		},
+		StateStore:      s,
+		WalkerCollector: wc,
+	}))
+	stop := ls.Start(t)
+	defer stop()
+
+	ls.Call(t, &langserver.CallRequest{
+		Method: "initialize",
+		ReqParams: fmt.Sprintf(`{
+		"capabilities": {},
+		"rootUri": %q,
+		"processId": 12345
+	}`, modUri)})
+	waitForWalkerPath(t, s, wc, document.DirHandleFromURI(modUri))
+	ls.Notify(t, &langserver.CallRequest{
+		Method:    "initialized",
+		ReqParams: "{}",
+	})
+
+	ls.CallAndExpectResponse(t, &langserver.CallRequest{
+		Method: "workspace/executeCommand",
+		ReqParams: fmt.Sprintf(`{
+		"command": %q,
+		"arguments": ["uri=%s"]
+	}`, cmd.Name("module.terraform"), modUri)}, `{
+		"jsonrpc": "2.0",
+		"id": 2,
+		"result": {
+			"v": 0,
+			"required_version": "~\u003e 0.15",
+			"discovered_version": "1.1.0"
+		}
+	}`)
+}

internal/langserver/handlers/handlers_test.go

@@ -76,7 +76,8 @@ func initializeResponse(t *testing.T, commandPrefix string) string {
 				"experimental": {
 					"referenceCountCodeLens": false,
 					"refreshModuleProviders": false,
-					"refreshModuleCalls": false
+					"refreshModuleCalls": false,
+					"refreshTerraformVersion": false
 				}
 			},
 			"serverInfo": {

internal/langserver/handlers/initialize.go

@@ -61,6 +61,10 @@ func (svc *service) Initialize(ctx context.Context, params lsp.InitializeParams)
 		expServerCaps.RefreshModuleCalls = true
 		properties["experimentalCapabilities.refreshModuleCalls"] = true
 	}
+	if _, ok := expClientCaps.RefreshTerraformVersionCommandId(); ok {
+		expServerCaps.RefreshTerraformVersion = true
+		properties["experimentalCapabilities.refreshTerraformVersion"] = true
+	}
 
 	serverCaps.Capabilities.Experimental = expServerCaps
 

internal/langserver/handlers/service.go

@@ -476,6 +476,10 @@ func (svc *service) configureSessionDependencies(ctx context.Context, cfgOpts *s
 			moduleHooks = append(moduleHooks, callRefreshClientCommand(svc.server, commandId))
 		}
 
+		if commandId, ok := lsp.ExperimentalClientCapabilities(cc.Experimental).RefreshTerraformVersionCommandId(); ok {
+			moduleHooks = append(moduleHooks, callRefreshClientCommand(svc.server, commandId))
+		}
+
 		if cc.Workspace.SemanticTokens.RefreshSupport {
 			moduleHooks = append(moduleHooks, refreshSemanticTokens(svc.server))
 		}

internal/protocol/experimental.go

@@ -1,9 +1,10 @@
 package protocol
 
 type ExperimentalServerCapabilities struct {
-	ReferenceCountCodeLens bool `json:"referenceCountCodeLens"`
-	RefreshModuleProviders bool `json:"refreshModuleProviders"`
-	RefreshModuleCalls     bool `json:"refreshModuleCalls"`
+	ReferenceCountCodeLens  bool `json:"referenceCountCodeLens"`
+	RefreshModuleProviders  bool `json:"refreshModuleProviders"`
+	RefreshModuleCalls      bool `json:"refreshModuleCalls"`
+	RefreshTerraformVersion bool `json:"refreshTerraformVersion"`
 }
 
 type ExpClientCapabilities map[string]interface{}
@@ -42,6 +43,15 @@ func (cc ExpClientCapabilities) RefreshModuleCallsCommandId() (string, bool) {
 	return cmdId, ok
 }
 
+func (cc ExpClientCapabilities) RefreshTerraformVersionCommandId() (string, bool) {
+	if cc == nil {
+		return "", false
+	}
+
+	cmdId, ok := cc["refreshTerraformVersionCommandId"].(string)
+	return cmdId, ok
+}
+
 func (cc ExpClientCapabilities) TelemetryVersion() (int, bool) {
 	if cc == nil {
 		return 0, false