vscode-languageclient/node#State TypeScript Examples

constructor (ctx: ExtensionContext, config: Config, emulatorState: EmulatorState, activeAccount: Account | null) {
    // Init running state with false and update, when client is connected to server
    this.running = false

    const activeAccountName = (activeAccount != null) ? activeAccount.name : ''
    const activeAccountAddress = (activeAccount != null) ? activeAccount.address : ''
    const { configPath } = config

    this.client = new LanguageClient(
      'cadence',
      'Cadence',
      {
        command: config.flowCommand,
        args: START_LANGUAGE_SERVER_ARGS
      },
      {
        documentSelector: [{ scheme: 'file', language: 'cadence' }],
        synchronize: {
          configurationSection: 'cadence'
        },
        initializationOptions: {
          accessCheckMode: config.accessCheckMode,
          configPath,
          emulatorState,
          activeAccountName,
          activeAccountAddress
        }
      }
    )

    this.client
      .onReady()
      .then(() =>
        window.showInformationMessage('Cadence language server started')
      )
      .catch((err: Error) =>
        window.showErrorMessage(`Cadence language server failed to start: ${err.message}`)
      )

    this.client.onDidChangeState((e: StateChangeEvent) => {
      this.running = e.newState === State.Running
    })

    const clientDisposable = this.client.start()
    ctx.subscriptions.push(clientDisposable)
  }

async restart(): Promise<void> {
        const startTime = Date.now()

        console.log('Restarting Lean Language Server')
        if (this.isStarted()) {
            await this.stop()
        }

        this.restartingEmitter.fire(undefined)
        this.toolchainPath = this.storageManager.getLeanPath();
        if (!this.toolchainPath) this.toolchainPath = toolchainPath();
        const version = this.storageManager.getLeanVersion();
        const env = addServerEnvPaths(process.env);
        if (serverLoggingEnabled()) {
            env.LEAN_SERVER_LOG_DIR = serverLoggingPath()
        }

        let executable = (this.toolchainPath) ? join(this.toolchainPath, 'bin', 'lake') : 'lake';

        // check if the lake process will start (skip it on scheme: 'untitled' files)
        let useLake = lakeEnabled() && this.folderUri && this.folderUri.scheme === 'file';
        if (useLake) {
            let knownDate = false;
            const lakefile = Uri.joinPath(this.folderUri, 'lakefile.lean')
            if (!await fileExists(new URL(lakefile.toString()))) {
                useLake = false;
            }
            else {
                // see if we can avoid the more expensive checkLakeVersion call.
                const date = await this.checkToolchainVersion(this.folderUri);
                if (date){
                    // Feb 16 2022 is when the 3.1.0.pre was released.
                    useLake = date >= new Date(2022, 1, 16);
                    knownDate = true;
                }
                if (useLake && !knownDate){
                    useLake = await this.checkLakeVersion(executable, version);
                }
            }
        }

        if (!useLake) {
            executable = (this.toolchainPath) ? join(this.toolchainPath, 'bin', 'lean') : 'lean';
        }

        let options = version ? ['+' + version] :[]
        if (useLake) {
            options = options.concat(['serve', '--'])
        } else{
            options = options.concat(['--server'])
        }

        // Add folder name to command-line so that it shows up in `ps aux`.
        if (this.folderUri) {
            options.push('' + this.folderUri.fsPath)
        } else {
            options.push('untitled')
        }

        const serverOptions: ServerOptions = {
            command: executable,
            args: options.concat(serverArgs()),
            options: {
                cwd: this.folderUri?.fsPath,
                env
            }
        }

        const documentSelector: DocumentFilter = {
            language: 'lean4'
        }

        if (this.folderUri){
            documentSelector.scheme = this.folderUri.scheme
            if (this.folderUri.scheme !== 'untitled') {
                documentSelector.pattern = `${this.folderUri.fsPath}/**/*`
            }
        }

        const clientOptions: LanguageClientOptions = {
            outputChannel: this.outputChannel,
            documentSelector: [documentSelector],
            workspaceFolder: this.workspaceFolder,
            initializationOptions: {
                editDelay: getElaborationDelay(), hasWidgets: true,
            },
            connectionOptions: {
                maxRestartCount: 0,
                cancellationStrategy: undefined as any,
            },
            middleware: {
                handleDiagnostics: (uri, diagnostics, next) => {
                    next(uri, diagnostics);
                    if (!this.client) return;
                    const uri_ = c2pConverter.asUri(uri);
                    const diagnostics_ = [];
                    for (const d of diagnostics) {
                        const d_: ls.Diagnostic = {
                            ...c2pConverter.asDiagnostic(d),
                        };
                        diagnostics_.push(d_);
                    }
                    this.diagnosticsEmitter.fire({uri: uri_, diagnostics: diagnostics_});
                },

                didOpen: async () => {
                    // Note: as per the LSP spec: An open notification must not be sent more than once
                    // without a corresponding close notification send before. This means open and close
                    // notification must be balanced and the max open count for a particular textDocument
                    // is one.  So this even does nothing the notification is handled by the
                    // openLean4Document method below after the 'lean4' languageId is established and
                    // it has weeded out documents opened to invisible editors (like 'git:' schemes and
                    // invisible editors created for Ctrl+Hover events.  A side effect of unbalanced
                    // open/close notification is leaking 'lean --worker' processes.
                    // See https://github.com/microsoft/vscode/issues/78453).
                    return;
                },

                didChange: async (data, next) => {
                    await next(data);
                    if (!this.running || !this.client) return; // there was a problem starting lean server.
                    const params = c2pConverter.asChangeTextDocumentParams(data);
                    this.didChangeEmitter.fire(params);
                },

                didClose: async (doc, next) => {
                    if (!this.isOpen.delete(doc.uri.toString())) {
                        return;
                    }
                    await next(doc);
                    if (!this.running || !this.client) return; // there was a problem starting lean server.
                    const params = c2pConverter.asCloseTextDocumentParams(doc);
                    this.didCloseEmitter.fire(params);
                },

                provideDocumentHighlights: async (doc, pos, ctok, next) => {
                    const leanHighlights = await next(doc, pos, ctok);
                    if (leanHighlights?.length) return leanHighlights;

                    // vscode doesn't fall back to textual highlights,
                    // so we need to do that manually
                    await new Promise((res) => setTimeout(res, 250));
                    if (ctok.isCancellationRequested) return;

                    const wordRange = doc.getWordRangeAtPosition(pos);
                    if (!wordRange) return;
                    const word = doc.getText(wordRange);

                    const highlights: DocumentHighlight[] = [];
                    const text = doc.getText();
                    const nonWordPattern = '[`~@$%^&*()-=+\\[{\\]}⟨⟩⦃⦄⟦⟧⟮⟯‹›\\\\|;:\",./\\s]|^|$'
                    const regexp = new RegExp(`(?<=${nonWordPattern})${escapeRegExp(word)}(?=${nonWordPattern})`, 'g')
                    for (const match of text.matchAll(regexp)) {
                        const start = doc.positionAt(match.index ?? 0)
                        highlights.push({
                            range: new Range(start, start.translate(0, match[0].length)),
                            kind: DocumentHighlightKind.Text,
                        })
                    }

                    return highlights;
                }
            },
        }
        this.client = new LanguageClient(
            'lean4',
            'Lean 4',
            serverOptions,
            clientOptions
        )
        let insideRestart = true;
        patchConverters(this.client.protocol2CodeConverter, this.client.code2ProtocolConverter)
        try {
            this.client.onDidChangeState(async (s) => {
                // see https://github.com/microsoft/vscode-languageserver-node/issues/825
                if (s.newState === State.Starting) {
                    console.log('client starting');
                } else if (s.newState === State.Running) {
                    const end = Date.now()
                    console.log('client running, started in ', end - startTime, 'ms');
                    this.running = true; // may have been auto restarted after it failed.
                    if (!insideRestart) {
                        this.restartedEmitter.fire(undefined)
                    }
                } else if (s.newState === State.Stopped) {
                    this.stoppedEmitter.fire('Lean language server has stopped. ');
                    console.log('client has stopped or it failed to start');
                    this.running = false;
                    if (!this.noPrompt){
                        await this.showRestartMessage();
                    }
                }
            })
            this.client.start()
            await this.client.onReady();
            // tell the new client about the documents that are already open!
            for (const key of this.isOpen.keys()) {
                const doc = this.isOpen.get(key);
                if (doc) this.notifyDidOpen(doc);
            }
            // if we got this far then the client is happy so we are running!
            this.running = true;
        } catch (error) {
            this.outputChannel.appendLine('' + error);
            this.serverFailedEmitter.fire('' + error);
            insideRestart = false;
            return;
        }

        // HACK(WN): Register a default notification handler to fire on custom notifications.
        // A mechanism to do this is provided in vscode-jsonrpc. One can register a `StarNotificationHandler`
        // here: https://github.com/microsoft/vscode-languageserver-node/blob/b2fc85d28a1a44c22896559ee5f4d3ba37a02ef5/jsonrpc/src/common/connection.ts#L497
        // which fires on any LSP notifications not in the standard, for example the `$/lean/..` ones.
        // However this mechanism is not exposed in vscode-languageclient, so we hack around its implementation.
        const starHandler = (method: string, params_: any) => {
            if (method === '$/lean/fileProgress' && this.client) {
                const params = params_ as LeanFileProgressParams;
                const uri = p2cConverter.asUri(params.textDocument.uri)
                this.progressChangedEmitter.fire([uri.toString(), params.processing]);
                // save the latest progress on this Uri in case infoview needs it later.
                this.progress.set(uri, params.processing);
            }

            this.customNotificationEmitter.fire({method, params: params_});
        };
        // eslint-disable-next-line @typescript-eslint/no-unsafe-argument
        this.client.onNotification(starHandler as any, () => {});

        // Reveal the standard error output channel when the server prints something to stderr.
        // The vscode-languageclient library already takes care of writing it to the output channel.
        (this.client as any)._serverProcess.stderr.on('data', () => {
            this.client?.outputChannel.show(true);
        });

        this.restartedEmitter.fire(undefined)
        insideRestart = false;
    }