denoify/src/lib/denoifyImportExportStatement.ts

For NPM module authors that would like to support Deno but do not want to write and maintain a port.

import * as path from "path";
import { assert, is } from "tsafe";
import * as fs from "fs";
import type { resolveNodeModuleToDenoModuleFactory } from "./resolveNodeModuleToDenoModule";
import type { getInstalledVersionPackageJsonFactory } from "./getInstalledVersionPackageJson";
import { ParsedImportExportStatement } from "./types/ParsedImportExportStatement";
import { consumeExecutableReplacerFactory } from "./replacer";
import { getProjectRoot } from "../tools/getProjectRoot";

/**
 * examples:
 * import { Evt } from "evt" -> import { Evt } from "https://deno.land/x/evt@.../mod.ts"
 * import { id } "evt/dist/tools/typeSafety" -> "https://deno.land/x/evt@.../deno_dist/tools/typeSafety/index.ts"
 * import * as interfaces from "./interfaces" -> import * as interfaces from "./interfaces/index.ts"
 */
export function denoifyImportExportStatementFactory(
    params: {
        userProvidedReplacerPath: string | undefined;
        getDestDirPath(params: { dirPath: string }): string;
    } & ReturnType<typeof resolveNodeModuleToDenoModuleFactory> &
        ReturnType<typeof getInstalledVersionPackageJsonFactory>
) {
    const { userProvidedReplacerPath, getDestDirPath, resolveNodeModuleToDenoModule, getInstalledVersionPackageJson } = params;

    const { consumeExecutableReplacer: consumeExecutableBuiltinsReplacer } = consumeExecutableReplacerFactory({
        "executableFilePath": path.join(
            getProjectRoot(),
            fs.existsSync(path.join(getProjectRoot(), "dist")) ? "dist" : "",
            "bin",
            "replacer",
            "index.js"
        )
    });

    const { consumeExecutableReplacer: consumeExecutableUserProvidedReplacer } =
        userProvidedReplacerPath === undefined
            ? { "consumeExecutableReplacer": undefined }
            : consumeExecutableReplacerFactory({
                  "executableFilePath": userProvidedReplacerPath
              });

    async function denoifyImportExportStatement(params: {
        /** Path of the file in which the import was */
        dirPath: string;
        /** e.g:
         * import { Evt } from "evt"
         * import { id } "evt/dist/tools/typeSafety"
         * import * as interfaces from "./interfaces"
         * ...
         */
        importExportStatement: string;
    }): Promise<string> {
        const { dirPath, importExportStatement } = params;

        const parsedImportExportStatement = ParsedImportExportStatement.parse(params.importExportStatement);

        if (parsedImportExportStatement.parsedArgument.type === "URL") {
            //There is no reason to have url import in the source
            //file as url import are not supported by node it does not
            //hurt to leave the import unchanged. See #7
            return importExportStatement;
        }

        const stringify = (argument: string) =>
            ParsedImportExportStatement.stringify({
                ...parsedImportExportStatement,
                "parsedArgument": ParsedImportExportStatement.ParsedArgument.parse(argument)
            });

        if (parsedImportExportStatement.parsedArgument.type === "PROJECT LOCAL FILE") {
            const { relativePath } = parsedImportExportStatement.parsedArgument;

            if (/\.json$/i.test(relativePath)) {
                return stringify(relativePath);
            }

            for (const ext of ["ts", "tsx"]) {
                if (fs.existsSync(path.join(dirPath, `${relativePath}.${ext}`))) {
                    return stringify(`${relativePath}.${ext}`);
                }
                if (relativePath.endsWith(`.${ext}`) && fs.existsSync(path.join(dirPath, relativePath))) {
                    return stringify(relativePath);
                }
            }

            // relative esm module import
            const esmReg = /\.m?js$/;
            if (esmReg.test(path.extname(relativePath)) && fs.existsSync(path.join(dirPath, relativePath.replace(esmReg, ".ts")))) {
                return stringify(relativePath.replace(esmReg, ".ts"));
            }

            const out = path.posix.join(relativePath, "index.ts");

            return stringify(out.startsWith(".") ? out : `./${out}`);
        }

        //NOTE: Should be inferable...
        assert(is<import("./replacer").ParsedImportExportStatement<"DEPENDENCY">>(parsedImportExportStatement));

        const { nodeModuleName, specificImportPath } = parsedImportExportStatement.parsedArgument;

        const { version } = await getInstalledVersionPackageJson({ nodeModuleName }).catch(() => ({ "version": "0.0.0" }));

        for (const consumeExecutableReplacer of [consumeExecutableUserProvidedReplacer, consumeExecutableBuiltinsReplacer]) {
            const result = await consumeExecutableReplacer?.({
                parsedImportExportStatement,
                version,
                "destDirPath": getDestDirPath({ dirPath })
            });

            if (result === undefined) {
                continue;
            }

            return result;
        }

        const nodeToDenoModuleResolutionResult = await resolveNodeModuleToDenoModule({ nodeModuleName });

        if (nodeToDenoModuleResolutionResult.result === "UNKNOWN BUILTIN") {
            return stringify(`node:${ParsedImportExportStatement.ParsedArgument.stringify(parsedImportExportStatement.parsedArgument)}`);
        }

        const { getValidImportUrl } = nodeToDenoModuleResolutionResult;

        return stringify(
            await getValidImportUrl(!specificImportPath ? { "target": "DEFAULT EXPORT" } : { "target": "SPECIFIC FILE", specificImportPath })
        );
    }

    return { denoifyImportExportStatement };
}