export async function checkTsconfig()

in src/checks.ts [61:141]
71 lines of code
31 McCabe index (conditional complexity)

export async function checkTsconfig(dirPath: string, dt: DefinitelyTypedInfo | undefined): Promise<void> {
    const options = await getCompilerOptions(dirPath);

    if (dt) {
        const { relativeBaseUrl } = dt;

        const mustHave = {
            module: "commonjs",
            noEmit: true,
            forceConsistentCasingInFileNames: true,
            baseUrl: relativeBaseUrl,
            typeRoots: [relativeBaseUrl],
            types: [],
        };

        for (const key of Object.getOwnPropertyNames(mustHave) as Array<keyof typeof mustHave>) {
            const expected = mustHave[key];
            const actual = options[key];
            if (!deepEquals(expected, actual)) {
                throw new Error(`Expected compilerOptions[${JSON.stringify(key)}] === ${JSON.stringify(expected)}`);
            }
        }

        for (const key in options) { // tslint:disable-line forin
            switch (key) {
                case "lib":
                case "noImplicitAny":
                case "noImplicitThis":
                case "strict":
                case "strictNullChecks":
                case "noUncheckedIndexedAccess":
                case "strictFunctionTypes":
                case "esModuleInterop":
                case "allowSyntheticDefaultImports":
                    // Allow any value
                    break;
                case "target":
                case "paths":
                case "jsx":
                case "jsxFactory":
                case "experimentalDecorators":
                case "noUnusedLocals":
                case "noUnusedParameters":
                    // OK. "paths" checked further by types-publisher
                    break;
                default:
                    if (!(key in mustHave)) {
                        throw new Error(`Unexpected compiler option ${key}`);
                    }
            }
        }
    }

    if (!("lib" in options)) {
        throw new Error('Must specify "lib", usually to `"lib": ["es6"]` or `"lib": ["es6", "dom"]`.');
    }

    if ("strict" in options) {
        if (options.strict !== true) {
            throw new Error('When "strict" is present, it must be set to `true`.');
        }

        for (const key of ["noImplicitAny", "noImplicitThis", "strictNullChecks", "strictFunctionTypes"]) {
            if (key in options) {
                throw new TypeError(`Expected "${key}" to not be set when "strict" is \`true\`.`);
            }
        }
    } else {
        for (const key of ["noImplicitAny", "noImplicitThis", "strictNullChecks", "strictFunctionTypes"]) {
            if (!(key in options)) {
                throw new Error(`Expected \`"${key}": true\` or \`"${key}": false\`.`);
            }
        }
    }

    if (options.types && options.types.length) {
        throw new Error(
            'Use `/// <reference types="..." />` directives in source files and ensure ' +
            'that the "types" field in your tsconfig is an empty array.');
    }
}