Add support for function signature help

go.mod

@@ -13,7 +13,7 @@ require (
 	github.com/hashicorp/go-uuid v1.0.3
 	github.com/hashicorp/go-version v1.6.0
 	github.com/hashicorp/hc-install v0.5.0
-	github.com/hashicorp/hcl-lang v0.0.0-20230310081458-97626944945e
+	github.com/hashicorp/hcl-lang v0.0.0-20230315123252-3faa6c8fba28
 	github.com/hashicorp/hcl/v2 v2.16.2
 	github.com/hashicorp/terraform-exec v0.18.1
 	github.com/hashicorp/terraform-json v0.16.0

go.sum

@@ -209,8 +209,8 @@ github.com/hashicorp/hc-install v0.5.0 h1:D9bl4KayIYKEeJ4vUDe9L5huqxZXczKaykSRcm
 github.com/hashicorp/hc-install v0.5.0/go.mod h1:JyzMfbzfSBSjoDCRPna1vi/24BEDxFaCPfdHtM5SCdo=
 github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
-github.com/hashicorp/hcl-lang v0.0.0-20230310081458-97626944945e h1:3VRs8PujogY3D+hKc9ChpKK7rP+y/WTaDAKjORrOxk8=
-github.com/hashicorp/hcl-lang v0.0.0-20230310081458-97626944945e/go.mod h1:m+ZB0CmTRHSo14j2INkDA+QZdzGBJRYTrOzf+4Xuj1k=
+github.com/hashicorp/hcl-lang v0.0.0-20230315123252-3faa6c8fba28 h1:7RUI5eMB9ULXn6+V9mNyGyM5o33FBzv8pad/W+aEx04=
+github.com/hashicorp/hcl-lang v0.0.0-20230315123252-3faa6c8fba28/go.mod h1:m+ZB0CmTRHSo14j2INkDA+QZdzGBJRYTrOzf+4Xuj1k=
 github.com/hashicorp/hcl/v2 v2.16.2 h1:mpkHZh/Tv+xet3sy3F9Ld4FyI2tUpWe9x3XtPx9f1a0=
 github.com/hashicorp/hcl/v2 v2.16.2/go.mod h1:JRmR89jycNkrrqnMmvPDMd56n1rQJ2Q6KocSLCMCXng=
 github.com/hashicorp/logutils v1.0.0/go.mod h1:QIAnNjmIWmVIIkWDTG1z5v++HQmx9WQRO+LraFDTW64=

internal/decoder/decoder.go

@@ -26,6 +26,7 @@ func modulePathContext(mod *state.Module, schemaReader state.SchemaReader, modRe
 		ReferenceOrigins: make(reference.Origins, 0),
 		ReferenceTargets: make(reference.Targets, 0),
 		Files:            make(map[string]*hcl.File, 0),
+		Functions:        coreFunctions(mod),
 	}
 
 	for _, origin := range mod.RefOrigins {

internal/decoder/functions.go

@@ -0,0 +1,41 @@
+package decoder
+
+import (
+	"github.com/hashicorp/go-version"
+	"github.com/hashicorp/hcl-lang/schema"
+	"github.com/hashicorp/terraform-ls/internal/state"
+	tfschema "github.com/hashicorp/terraform-schema/schema"
+)
+
+func coreFunctions(mod *state.Module) map[string]schema.FunctionSignature {
+	if mod.TerraformVersion != nil {
+		s, err := tfschema.FunctionsForVersion(mod.TerraformVersion)
+		if err == nil {
+			return s
+		}
+		if mod.TerraformVersion.LessThan(tfschema.OldestAvailableVersion) {
+			return mustFunctionsForVersion(tfschema.OldestAvailableVersion)
+		}
+
+		return mustFunctionsForVersion(tfschema.LatestAvailableVersion)
+	}
+
+	s, err := tfschema.FunctionsForConstraint(mod.Meta.CoreRequirements)
+	if err == nil {
+		return s
+	}
+	if mod.Meta.CoreRequirements.Check(tfschema.OldestAvailableVersion) {
+		return mustFunctionsForVersion(tfschema.OldestAvailableVersion)
+	}
+
+	return mustFunctionsForVersion(tfschema.LatestAvailableVersion)
+}
+
+func mustFunctionsForVersion(v *version.Version) map[string]schema.FunctionSignature {
+	s, err := tfschema.FunctionsForVersion(v)
+	if err != nil {
+		// this should never happen
+		panic(err)
+	}
+	return s
+}

internal/langserver/handlers/handlers_test.go

@@ -41,7 +41,9 @@ func initializeResponse(t *testing.T, commandPrefix string) string {
 					"completionItem":{}
 				},
 				"hoverProvider": true,
-				"signatureHelpProvider": {},
+				"signatureHelpProvider": {
+					"triggerCharacters":["(",","]
+				},
 				"declarationProvider": {},
 				"definitionProvider": true,
 				"referencesProvider": true,

internal/langserver/handlers/initialize.go

@@ -246,6 +246,9 @@ func initializeResult(ctx context.Context) lsp.InitializeResult {
 					ChangeNotifications: "workspace/didChangeWorkspaceFolders",
 				},
 			},
+			SignatureHelpProvider: lsp.SignatureHelpOptions{
+				TriggerCharacters: []string{"(", ","},
+			},
 		},
 	}
 

internal/langserver/handlers/service.go

@@ -272,6 +272,16 @@ func (svc *service) Assigner() (jrpc2.Assigner, error) {
 
 			return handle(ctx, req, svc.TextDocumentFormatting)
 		},
+		"textDocument/signatureHelp": func(ctx context.Context, req *jrpc2.Request) (interface{}, error) {
+			err := session.CheckInitializationIsConfirmed()
+			if err != nil {
+				return nil, err
+			}
+
+			ctx = ilsp.WithClientCapabilities(ctx, cc)
+
+			return handle(ctx, req, svc.SignatureHelp)
+		},
 		"textDocument/semanticTokens/full": func(ctx context.Context, req *jrpc2.Request) (interface{}, error) {
 			err := session.CheckInitializationIsConfirmed()
 			if err != nil {

internal/langserver/handlers/signature_help.go

@@ -0,0 +1,38 @@
+package handlers
+
+import (
+	"context"
+
+	ilsp "github.com/hashicorp/terraform-ls/internal/lsp"
+	lsp "github.com/hashicorp/terraform-ls/internal/protocol"
+)
+
+func (svc *service) SignatureHelp(ctx context.Context, params lsp.SignatureHelpParams) (*lsp.SignatureHelp, error) {
+	_, err := ilsp.ClientCapabilities(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	dh := ilsp.HandleFromDocumentURI(params.TextDocument.URI)
+	doc, err := svc.stateStore.DocumentStore.GetDocument(dh)
+	if err != nil {
+		return nil, err
+	}
+
+	d, err := svc.decoderForDocument(ctx, doc)
+	if err != nil {
+		return nil, err
+	}
+
+	pos, err := ilsp.HCLPositionFromLspPosition(params.Position, doc)
+	if err != nil {
+		return nil, err
+	}
+
+	sig, err := d.SignatureAtPos(doc.Filename, pos)
+	if err != nil {
+		return nil, err
+	}
+
+	return ilsp.ToSignatureHelp(sig), nil
+}

internal/langserver/handlers/signature_help_test.go

@@ -0,0 +1,150 @@
+package handlers
+
+import (
+	"encoding/json"
+	"fmt"
+	"testing"
+
+	"github.com/hashicorp/go-version"
+	tfjson "github.com/hashicorp/terraform-json"
+	"github.com/hashicorp/terraform-ls/internal/langserver"
+	"github.com/hashicorp/terraform-ls/internal/langserver/session"
+	"github.com/hashicorp/terraform-ls/internal/state"
+	"github.com/hashicorp/terraform-ls/internal/terraform/exec"
+	"github.com/hashicorp/terraform-ls/internal/walker"
+	"github.com/stretchr/testify/mock"
+)
+
+func TestSignatureHelp_withoutInitialization(t *testing.T) {
+	ls := langserver.NewLangServerMock(t, NewMockSession(nil))
+	stop := ls.Start(t)
+	defer stop()
+
+	ls.CallAndExpectError(t, &langserver.CallRequest{
+		Method: "textDocument/signatureHelp",
+		ReqParams: fmt.Sprintf(`{
+			"textDocument": {
+				"uri": "%s/main.tf"
+			},
+			"position": {
+				"character": 0,
+				"line": 1
+			},
+			"context": {
+				"isRetrigger": false,
+				"triggerCharacter": "(",
+				"triggerKind": 2
+			}
+		}`, TempDir(t).URI)}, session.SessionNotInitialized.Err())
+}
+
+func TestSignatureHelp_withValidData(t *testing.T) {
+	tmpDir := TempDir(t)
+	InitPluginCache(t, tmpDir.Path())
+
+	var testSchema tfjson.ProviderSchemas
+	err := json.Unmarshal([]byte(testModuleSchemaOutput), &testSchema)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ss, err := state.NewStateStore()
+	if err != nil {
+		t.Fatal(err)
+	}
+	wc := walker.NewWalkerCollector()
+
+	ls := langserver.NewLangServerMock(t, NewMockSession(&MockSessionInput{
+		TerraformCalls: &exec.TerraformMockCalls{
+			PerWorkDir: map[string][]*mock.Call{
+				tmpDir.Path(): {
+					{
+						Method:        "Version",
+						Repeatability: 1,
+						Arguments: []interface{}{
+							mock.AnythingOfType(""),
+						},
+						ReturnArguments: []interface{}{
+							version.Must(version.NewVersion("0.12.0")),
+							nil,
+							nil,
+						},
+					},
+					{
+						Method:        "GetExecPath",
+						Repeatability: 1,
+						ReturnArguments: []interface{}{
+							"",
+						},
+					},
+					{
+						Method:        "ProviderSchemas",
+						Repeatability: 1,
+						Arguments: []interface{}{
+							mock.AnythingOfType(""),
+						},
+						ReturnArguments: []interface{}{
+							&testSchema,
+							nil,
+						},
+					},
+				},
+			},
+		},
+		StateStore:      ss,
+		WalkerCollector: wc,
+	}))
+	stop := ls.Start(t)
+	defer stop()
+
+	ls.Call(t, &langserver.CallRequest{
+		Method: "initialize",
+		ReqParams: fmt.Sprintf(`{
+		"capabilities": {},
+		"rootUri": %q,
+		"processId": 12345
+	}`, tmpDir.URI)})
+	waitForWalkerPath(t, ss, wc, tmpDir)
+	ls.Notify(t, &langserver.CallRequest{
+		Method:    "initialized",
+		ReqParams: "{}",
+	})
+	ls.Call(t, &langserver.CallRequest{
+		Method: "textDocument/didOpen",
+		ReqParams: fmt.Sprintf(`{
+		"textDocument": {
+			"version": 0,
+			"languageId": "terraform",
+			"text": "variable \"name\" {\n  default = file(\"~/foo\")\n}",
+			"uri": "%s/main.tf"
+		}
+	}`, TempDir(t).URI)})
+	waitForAllJobs(t, ss)
+
+	ls.CallAndExpectResponse(t, &langserver.CallRequest{
+		Method: "textDocument/signatureHelp",
+		ReqParams: fmt.Sprintf(`{
+			"textDocument": {
+				"uri": "%s/main.tf"
+			},
+			"position": {
+				"character": 16,
+				"line": 1
+			},
+			"context": {
+				"isRetrigger": false,
+				"triggerCharacter": "(",
+				"triggerKind": 2
+			}
+		}`, TempDir(t).URI)}, `{
+			"jsonrpc": "2.0",
+			"id": 3,
+			"result": {
+				"signatures": [{
+					"label": "file(path string) string",
+					"documentation": "file reads the contents of a file at the given path and returns them as a string.",
+					"parameters": [{"label": "path"}]
+				}]
+			}
+		}`)
+}

internal/lsp/signature.go

@@ -0,0 +1,35 @@
+package lsp
+
+import (
+	"github.com/hashicorp/hcl-lang/lang"
+	"github.com/hashicorp/terraform-ls/internal/mdplain"
+	lsp "github.com/hashicorp/terraform-ls/internal/protocol"
+)
+
+func ToSignatureHelp(signature *lang.FunctionSignature) *lsp.SignatureHelp {
+	if signature == nil {
+		return nil
+	}
+
+	parameters := make([]lsp.ParameterInformation, 0, len(signature.Parameters))
+	for _, p := range signature.Parameters {
+		parameters = append(parameters, lsp.ParameterInformation{
+			Label: p.Name,
+			// TODO: Support markdown per https://github.com/hashicorp/terraform-ls/issues/1212
+			Documentation: mdplain.Clean(p.Description.Value),
+		})
+	}
+
+	return &lsp.SignatureHelp{
+		Signatures: []lsp.SignatureInformation{
+			{
+				Label: signature.Name,
+				// TODO: Support markdown per https://github.com/hashicorp/terraform-ls/issues/1212
+				Documentation: mdplain.Clean(signature.Description.Value),
+				Parameters:    parameters,
+			},
+		},
+		ActiveParameter: signature.ActiveParameter,
+		ActiveSignature: 0,
+	}
+}