ts-server.js

script.ts

importScripts("https://unpkg.com/@typescript/vfs@1.3.5/dist/vfs.globals.js");
importScripts(
    "https://cdnjs.cloudflare.com/ajax/libs/typescript/4.4.3/typescript.min.js"
);
importScripts("https://unpkg.com/@okikio/emitter@2.1.7/lib/api.js");

export type VFS = typeof import("https://cdn.esm.sh/@typescript/vfs");
export type EVENT_EMITTER = import("https://cdn.esm.sh/@okikio/emitter").EventEmitter;
export type Diagnostic = import("https://cdn.esm.sh/@codemirror/lint").Diagnostic;

var {
    createDefaultMapFromCDN,
    createSystem,
    createVirtualTypeScriptEnvironment
} = globalThis.tsvfs as VFS;
var ts = globalThis.ts; // as TS

var EventEmitter = globalThis.emitter.EventEmitter;
var _emitter: EVENT_EMITTER = new EventEmitter();

globalThis.localStorage = globalThis.localStorage ?? ({} as Storage);

(async () => {
    const compilerOpts = {
        target: ts.ScriptTarget.ES2021,
        module: ts.ScriptTarget.ES2020,
        lib: ["es2021", "es2020", "dom", "webworker"],
        esModuleInterop: true
    };

    let initialText = "const hello = 'hi'";
    _emitter.once("updateText", (details) => {
        initialText = details.text.join("\n");
    });

    const fsMap = await createDefaultMapFromCDN(
        compilerOpts,
        ts.version,
        false,
        ts
    );
    const ENTRY_POINT = "index.ts";
    fsMap.set(ENTRY_POINT, initialText);

    const system = createSystem(fsMap);
    const env = createVirtualTypeScriptEnvironment(
        system,
        [ENTRY_POINT],
        ts,
        compilerOpts
    );

    // You can then interact with the languageService to introspect the code
    postMessage({
        event: "ready",
        details: []
    });

    _emitter.on("updateText", (details) => {
        env.updateFile(ENTRY_POINT, [].concat(details.text).join("\n"));
        // console.log(details.text)
    });

    _emitter.on("autocomplete-request", ({ pos }) => {
        let result = env.languageService.getCompletionsAtPosition(
            ENTRY_POINT,
            pos,
            {}
        );

        postMessage({
            event: "autocomplete-results",
            details: result
        });
    });

    _emitter.on("tooltip-request", ({ pos }) => {
        let result = env.languageService.getQuickInfoAtPosition(
            ENTRY_POINT,
            pos
        );

        postMessage({
            event: "tooltip-results",
            details: result
                ? {
                      result,
                      tootltipText:
                          ts.displayPartsToString(result.displayParts) +
                          (result.documentation?.length
                              ? "\n" +
                                ts.displayPartsToString(result.documentation)
                              : "")
                  }
                : { result, tooltipText: "" }
        });
    });

    _emitter.on("lint-request", () => {
        let SyntacticDiagnostics = env.languageService.getSyntacticDiagnostics(
            ENTRY_POINT
        );
        let SemanticDiagnostic = env.languageService.getSemanticDiagnostics(
            ENTRY_POINT
        );
        let SuggestionDiagnostics = env.languageService.getSuggestionDiagnostics(
            ENTRY_POINT
        );

        type Diagnostics = typeof SyntacticDiagnostics &
            typeof SemanticDiagnostic &
            typeof SuggestionDiagnostics;
        let result: Diagnostics = [].concat(
            SyntacticDiagnostics,
            SemanticDiagnostic,
            SuggestionDiagnostics
        );

        postMessage({
            event: "lint-results",
            details: result.map((v) => {
                let from = v.start;
                let to = v.start + v.length;
                // let codeActions = env.languageService.getCodeFixesAtPosition(ENTRY_POINT, from, to, [v.category], {}, {});

                let diag: Diagnostic = {
                    from,
                    to,
                    message: v.messageText as string,
                    source: v?.source,
                    severity: ["warning", "error", "info", "info"][
                        v.category
                    ] as Diagnostic["severity"]
                    // actions: codeActions as any as Diagnostic["actions"]
                };

                return diag;
            })
        });
    });
})();

addEventListener(
    "message",
    ({ data }: MessageEvent<{ event: string; details: any }>) => {
        let { event, details } = data;
        _emitter.emit(event, details);
    }
);

ts-server-js.markdown

ts-server.js

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