@eeue56/bach/src/bach.ts

A simple TypeScript test runner inspired by Pytest.

#!/usr/bin/env node
import type { Result } from "@eeue56/baner";
import {
    bothFlag,
    empty,
    help,
    longFlag,
    number,
    parse,
    parser,
    string,
    variableList,
} from "@eeue56/baner";
import assert from "assert";
import { promises as fsPromises } from "fs";
import { glob } from "fs/promises";
import JSON5 from "json5";
import * as path from "path";
import { performance } from "perf_hooks";
import { fileURLToPath } from "url";

const AsyncFunction = Object.getPrototypeOf(async function () {}).constructor;

type SingleFileResult = {
    functionName: string;
    passed: boolean;
};

type SingleFileCellSizes = {
    functionName: number;
    passed: number;
};

type MultipleFileResult = {
    fileName: string;
    passed: number;
    failed: number;
};

type MultipleFileCellSizes = {
    fileName: number;
    passed: number;
    failed: number;
};

const chalk = {
    red: function (text: string): string {
        return `\x1b[31m${text}\x1b[0m`;
    },
    green: function (text: string): string {
        return `\x1b[32m\x1b[1m${text}\x1b[0m`;
    },
};

function widestSingleFileCellSizes(
    results: SingleFileResult[],
): SingleFileCellSizes {
    const cellSizes: SingleFileCellSizes = {
        functionName: " Function name ".length,
        passed: " Passed? ".length,
    };

    for (const result of results) {
        if (cellSizes.functionName < result.functionName.length + 2) {
            cellSizes.functionName = result.functionName.length + 2;
        }

        if (cellSizes.passed < `${result.passed}`.length + 2) {
            cellSizes.passed = `${result.passed}`.length + 2;
        }
    }
    return {
        functionName:
            cellSizes.functionName % 2 === 0
                ? cellSizes.functionName
                : cellSizes.functionName + 1,
        passed:
            cellSizes.passed % 2 === 0
                ? cellSizes.passed
                : cellSizes.passed + 1,
    };
}

function widestMultipleFileCellSizes(
    results: MultipleFileResult[],
): MultipleFileCellSizes {
    const cellSizes: MultipleFileCellSizes = {
        fileName: " Function name ".length,
        passed: " Passed ".length,
        failed: " Failed ".length,
    };

    for (const result of results) {
        if (cellSizes.fileName < result.fileName.length + 2) {
            cellSizes.fileName = result.fileName.length + 2;
        }

        if (cellSizes.passed < `${result.passed}`.length + 2) {
            cellSizes.passed = `${result.passed}`.length + 2;
        }

        if (cellSizes.failed < `${result.failed}`.length + 2) {
            cellSizes.failed = `${result.failed}`.length + 2;
        }
    }
    return {
        fileName:
            cellSizes.fileName % 2 === 0
                ? cellSizes.fileName
                : cellSizes.fileName + 1,
        passed:
            cellSizes.passed % 2 === 0
                ? cellSizes.passed
                : cellSizes.passed + 1,
        failed:
            cellSizes.failed % 2 === 0
                ? cellSizes.failed
                : cellSizes.failed + 1,
    };
}

const horizontal = "─";
const vertical = "│";
const leftJoin = "├";
const middleJoin = "┼";
const rightJoin = "┤";
const leftCorner = "┌";
const rightCorner = "┐";
const bottomLeftCorner = "└";
const bottomRightCorner = "┘";

export function centerAndPadding(cellSize: number, text: string): string {
    const length = text.length;
    const eitherSide = Math.floor((cellSize - length) / 2);

    let extraLeft = 0;
    if (text.length % 2 === 1) {
        extraLeft = 1;
    }
    return " ".repeat(eitherSide + extraLeft) + text + " ".repeat(eitherSide);
}

function viewSingleFileResult(
    result: SingleFileResult,
    tableWidth: SingleFileCellSizes,
): void {
    console.log(
        leftJoin +
            horizontal.repeat(tableWidth.functionName) +
            middleJoin +
            horizontal.repeat(tableWidth.passed) +
            rightJoin,
    );

    const colouredFunctionName = result.passed
        ? chalk.green(
              centerAndPadding(
                  tableWidth.functionName,
                  `${result.functionName}`,
              ),
          )
        : chalk.red(
              centerAndPadding(
                  tableWidth.functionName,
                  `${result.functionName}`,
              ),
          );

    const colouredPassed = result.passed
        ? chalk.green(centerAndPadding(tableWidth.passed, `${result.passed}`))
        : chalk.red(centerAndPadding(tableWidth.passed, `${result.passed}`));

    console.log(
        vertical + colouredFunctionName + vertical + colouredPassed + vertical,
    );
}

function viewSingleFileResults(results: SingleFileResult[]): void {
    const cellSizes = widestSingleFileCellSizes(results);
    const headers =
        vertical +
        centerAndPadding(cellSizes.functionName, "Function name") +
        vertical +
        centerAndPadding(cellSizes.passed, "Passed?") +
        vertical;

    console.log(
        leftCorner +
            horizontal.repeat(cellSizes.functionName + cellSizes.passed + 1) +
            rightCorner,
    );
    console.log(headers);

    for (const result of results) {
        viewSingleFileResult(result, cellSizes);
    }
    console.log(
        bottomLeftCorner +
            horizontal.repeat(cellSizes.functionName) +
            horizontal.repeat(cellSizes.passed + 1) +
            bottomRightCorner,
    );
}

function viewMultipleFileResult(
    result: MultipleFileResult,
    tableWidth: MultipleFileCellSizes,
): void {
    console.log(
        leftJoin +
            horizontal.repeat(tableWidth.fileName) +
            middleJoin +
            horizontal.repeat(tableWidth.passed) +
            middleJoin +
            horizontal.repeat(tableWidth.failed) +
            rightJoin,
    );

    const colouredFileName =
        result.failed === 0
            ? chalk.green(
                  centerAndPadding(tableWidth.fileName, `${result.fileName}`),
              )
            : chalk.red(
                  centerAndPadding(tableWidth.fileName, `${result.fileName}`),
              );

    const colouredPassed =
        result.passed > 0
            ? chalk.green(
                  centerAndPadding(tableWidth.passed, `${result.passed}`),
              )
            : chalk.red(
                  centerAndPadding(tableWidth.passed, `${result.passed}`),
              );

    const colouredFailed =
        result.failed === 0
            ? chalk.green(
                  centerAndPadding(tableWidth.failed, `${result.failed}`),
              )
            : chalk.red(
                  centerAndPadding(tableWidth.failed, `${result.failed}`),
              );

    console.log(
        vertical +
            colouredFileName +
            vertical +
            colouredPassed +
            vertical +
            colouredFailed +
            vertical,
    );
}

function viewMultipleFileResults(results: MultipleFileResult[]): void {
    const cellSizes = widestMultipleFileCellSizes(results);
    const headers =
        vertical +
        centerAndPadding(cellSizes.fileName, "File name") +
        vertical +
        centerAndPadding(cellSizes.passed, "Passed") +
        vertical +
        centerAndPadding(cellSizes.failed, "Failed") +
        vertical;

    console.log(
        leftCorner +
            horizontal.repeat(
                cellSizes.fileName + cellSizes.passed + cellSizes.failed + 2,
            ) +
            rightCorner,
    );
    console.log(headers);

    for (const result of results) {
        viewMultipleFileResult(result, cellSizes);
    }
    console.log(
        bottomLeftCorner +
            horizontal.repeat(
                cellSizes.fileName + cellSizes.passed + cellSizes.failed + 2,
            ) +
            bottomRightCorner,
    );
}

function isAsyncFunction(func: any): boolean {
    return Object.getPrototypeOf(func).constructor === AsyncFunction;
}

function getSnapshotFileName(
    config: any,
    fileName: string,
    functionName: string,
): string {
    return path.join(
        config.include[0].split("/")[0],
        `__snapshots__`,
        path
            .relative(process.cwd(), fileName)
            .split(".")
            .slice(0, -1)
            .join("."),
        functionName + ".ts",
    );
}

async function updateSnapshots(
    config: any,
    fileArgument: Result<string[]>,
    filesToProcess: string[],
    functionNamesToRun: string[] | null,
): Promise<void> {
    let totalSnapshotsUpdated = 0;
    await Promise.all(
        filesToProcess.map(async (fileName: string): Promise<null> => {
            return new Promise(async (resolve, reject): Promise<void> => {
                fileName =
                    fileArgument.kind === "Ok"
                        ? path.join(process.cwd(), fileName)
                        : fileName;
                const baseFileName = path
                    .basename(fileName)
                    .split(".")
                    .slice(0, -1)
                    .join(".");

                const extension = path.extname(fileName);
                const isValidExtension =
                    extension === ".js" || extension === ".ts";

                if (!baseFileName.endsWith("test") || !isValidExtension) {
                    return resolve(null);
                }

                console.log(`Found ${fileName}`);
                const imported = await import(fileName);
                for (const functionName of Object.keys(imported)) {
                    if (!functionName.startsWith("snapshot")) {
                        continue;
                    }
                    if (
                        functionNamesToRun &&
                        functionNamesToRun.indexOf(functionName) === -1
                    )
                        continue;

                    const func = imported[functionName];
                    const isAsync = isAsyncFunction(func);

                    totalSnapshotsUpdated += 1;

                    console.log(`Running ${functionName}`);

                    let computedSnapshot;
                    if (isAsync) {
                        computedSnapshot = await func();
                    } else {
                        computedSnapshot = func();
                    }

                    const snapshotFileName = getSnapshotFileName(
                        config,
                        fileName,
                        functionName,
                    );

                    console.log("writing to ", snapshotFileName);

                    let fileContents = computedSnapshot;

                    const strToWrite = `
export const ${functionName} = ${JSON.stringify(fileContents, null, 4)};
                            `.trim();

                    await fsPromises.mkdir(path.dirname(snapshotFileName), {
                        recursive: true,
                    });
                    await fsPromises.writeFile(snapshotFileName, strToWrite);
                }

                resolve(null);
            });
        }),
    );

    console.log(`Updated ${totalSnapshotsUpdated} snapshots.`);
}

type Results = { [filename: string]: { [functionName: string]: boolean } };

/**
 * Turn includes (e.g `src`) into glob-friendly versions (e.g `src/**`)
 */
function globifyIncludes(includes: string[]): string[] {
    return includes.map((pattern) => {
        if (pattern.endsWith("/")) {
            return `${pattern}**`;
        } else if (!pattern.endsWith("*")) {
            return `${pattern}/**`;
        }

        return pattern;
    });
}

const cliParser = parser(
    longFlag("function", "Run a specific function", variableList(string())),
    longFlag("file", "Run a specific file", variableList(string())),
    longFlag(
        "clean-exit",
        "Don't use process.exit even if tests fail",
        empty(),
    ),
    longFlag("only-fails", "Only show the tests that fail", empty()),
    longFlag(
        "in-chunks",
        "Run tests in chunks of N files (suitable for lower memory impact)",
        number(),
    ),
    longFlag("chunk-start", "Start running chunk at N", number()),
    bothFlag("u", "update-snapshots", "Update the snapshots and exit", empty()),
    bothFlag("h", "help", "Displays help message", empty()),
);

export async function runner(): Promise<any> {
    const program = parse(cliParser, process.argv);

    if (program.flags["help"].isPresent) {
        console.log(help(cliParser));
        return;
    }

    const onlyFails =
        program.flags["only-fails"].arguments.kind === "Ok" &&
        program.flags["only-fails"].arguments.value;

    const functionNamesToRun: string[] | null =
        program.flags.function.arguments.kind === "Ok"
            ? program.flags.function.arguments.value
            : null;

    const fileNamesToRun: string[] | null =
        program.flags.file.arguments.kind === "Ok"
            ? program.flags.file.arguments.value
            : null;

    console.log("Looking for tsconfig...");
    const strConfig = (await fsPromises.readFile("./tsconfig.json")).toString();
    const config = JSON5.parse(strConfig);

    if (!fileNamesToRun) {
        console.log(`Looking for tests in ${config.include}...`);
        if (!config.include) {
            console.error(
                "include was not set in tsconfig, not sure where to look for tests",
            );
            console.error("Quitting...");
            return;
        }
    } else {
        console.log("Running provided filenames...");
    }

    let includes: string[] = [];
    if (config.include) {
        includes = globifyIncludes(config.include as string[]);
    }

    const files = fileNamesToRun ? fileNamesToRun : [];

    if (!fileNamesToRun) {
        for await (const file of glob(includes, { withFileTypes: true })) {
            if (file.isFile()) {
                files.push(path.join(file.parentPath, file.name));
            }
        }
    }

    // warn if no files are found
    if (files.length === 0) {
        console.log("No matching files were found");
        if (fileNamesToRun) {
            if (fileNamesToRun.length === 1) {
                console.log(`Does ${fileNamesToRun.join()} exist?`);
            } else {
                console.log(`Do ${fileNamesToRun.join(", ")} exist?`);
            }
        } else {
            console.log(
                `Does the 'include' found in tsconfig (${includes}) include the right files?`,
            );
        }
    }

    const results: Results = {};

    let passedTests = 0;
    let totalTests = 0;

    const chunks =
        program.flags["in-chunks"].arguments.kind == "Ok"
            ? program.flags["in-chunks"].arguments.value
            : files.length;

    const chunkStart =
        program.flags["chunk-start"].arguments.kind == "Ok"
            ? program.flags["chunk-start"].arguments.value
            : 0;

    const startTime = performance.now();

    const filesToProcess = files.slice(chunkStart, chunkStart + chunks);

    if (
        program.flags["update-snapshots"].arguments.kind === "Ok" &&
        program.flags["update-snapshots"].arguments.value
    ) {
        await updateSnapshots(
            config,
            program.flags.file.arguments,
            filesToProcess,
            functionNamesToRun,
        );
        return;
    }

    await Promise.all(
        filesToProcess.map(async (fileName: string): Promise<null> => {
            return new Promise(async (resolve, reject): Promise<void> => {
                fileName =
                    program.flags.file.arguments.kind === "Ok"
                        ? path.join(process.cwd(), fileName)
                        : fileName;
                const baseFileName = path
                    .basename(fileName)
                    .split(".")
                    .slice(0, -1)
                    .join(".");

                const extension = path.extname(fileName);
                const isValidExtension =
                    extension === ".js" || extension === ".ts";

                const isASpecificFile =
                    program.flags.file.arguments.kind === "Ok";

                if (!isASpecificFile) {
                    if (!baseFileName.endsWith("test") || !isValidExtension) {
                        return resolve(null);
                    }
                }

                results[fileName] = {};
                console.log(`Found ${fileName}`);
                const imported = await import(fileName);
                for (const functionName of Object.keys(imported)) {
                    if (functionName.startsWith("test")) {
                        if (
                            functionNamesToRun &&
                            functionNamesToRun.indexOf(functionName) === -1
                        )
                            continue;

                        const func = imported[functionName];
                        const isAsync = isAsyncFunction(func);

                        totalTests += 1;

                        if (!onlyFails) console.log(`Running ${functionName}`);

                        try {
                            if (isAsync) {
                                await func();
                            } else {
                                func();
                            }
                            results[fileName][functionName] = true;
                            passedTests += 1;
                        } catch (e) {
                            results[fileName][functionName] = false;
                            console.error(
                                chalk.red(
                                    `${fileName} ${functionName} failed.`,
                                ),
                            );
                            console.error(e);
                        }
                    } else if (functionName.startsWith("snapshot")) {
                        if (
                            functionNamesToRun &&
                            functionNamesToRun.indexOf(functionName) === -1
                        )
                            continue;

                        const func = imported[functionName];
                        const isAsync = isAsyncFunction(func);

                        totalTests += 1;

                        if (!onlyFails) console.log(`Running ${functionName}`);

                        try {
                            let computedSnapshot;
                            if (isAsync) {
                                computedSnapshot = await func();
                            } else {
                                computedSnapshot = func();
                            }

                            const snapshotFileName = getSnapshotFileName(
                                config,
                                fileName,
                                functionName,
                            );

                            let fileContents = computedSnapshot;

                            try {
                                fileContents = (
                                    await import(
                                        path.join(
                                            process.cwd(),
                                            snapshotFileName,
                                        )
                                    )
                                )[functionName];
                            } catch (e) {
                                console.log(
                                    "Creating snapshot for the first time...",
                                );

                                const strToWrite = `
export const ${functionName} = ${JSON.stringify(fileContents, null, 4)};
                                `.trim();

                                await fsPromises.mkdir(
                                    path.dirname(snapshotFileName),
                                    { recursive: true },
                                );
                                await fsPromises.writeFile(
                                    snapshotFileName,
                                    strToWrite,
                                );
                            }

                            assert.deepStrictEqual(
                                computedSnapshot,
                                fileContents,
                            );

                            results[fileName][functionName] = true;
                            passedTests += 1;
                        } catch (e) {
                            results[fileName][functionName] = false;
                            console.error(
                                chalk.red(
                                    `${fileName} ${functionName} failed.`,
                                ),
                            );
                            console.error(e);
                        }
                    }
                }

                resolve(null);
            });
        }),
    );
    if (filesToProcess.length < files.length) {
        console.log(
            `Ran ${chunks} files, starting at ${chunkStart}, out of ${
                files.length
            } total. New start should be ${chunkStart + chunks}`,
        );
    }

    const endTime = performance.now();

    if (program.flags["file"].arguments.kind === "Ok") {
        const formattedResults: SingleFileResult[] = [];

        for (const fileName of Object.keys(results)) {
            const functions = results[fileName];

            for (const functionName of Object.keys(functions)) {
                formattedResults.push({
                    functionName,
                    passed: functions[functionName],
                });
            }
        }
        if (onlyFails) {
            viewSingleFileResults(
                formattedResults.filter((result) => result.passed === false),
            );
        } else {
            viewSingleFileResults(formattedResults);
        }
    } else {
        const formattedResults: MultipleFileResult[] = Object.entries(
            results,
        ).map(([fileName, functions]) => {
            let passed = 0;
            Object.entries(functions).forEach(([functionName, didPass]) => {
                if (didPass) passed += 1;
            });
            const failed = Object.keys(functions).length - passed;

            return {
                fileName,
                passed,
                failed,
            };
        });

        if (onlyFails) {
            viewMultipleFileResults(
                formattedResults.filter((result) => result.failed > 0),
            );
        } else {
            viewMultipleFileResults(formattedResults);
        }
    }

    console.log(
        `Ran ${totalTests} tests in ${Math.floor(
            endTime - startTime,
        )}ms. ${passedTests} tests passed, ${totalTests - passedTests} failed`,
    );

    const shouldCleanExit =
        program.flags["clean-exit"].arguments.kind === "Ok" &&
        program.flags["clean-exit"].arguments.value;

    if (totalTests - passedTests > 0 && !shouldCleanExit) {
        process.exit(1);
    }
}

const isMain = () => {
    const entryPointPath = fileURLToPath(`file://${process.argv[1]}`);

    if (entryPointPath.endsWith(".bin/bach")) {
        return true;
    }

    if (!import.meta.url) {
        return require.main === module;
    }

    const currentFilePath = fileURLToPath(import.meta.url);
    return currentFilePath === entryPointPath;
};

if (isMain()) {
    runner();
}