@dvsa/mes-test-schema/generateSchemas.ts

Domain model for data associated with tests administered by the Driving Examiner Services project

declare var require: any;
declare var process: any;

const merge = require('deepmerge');
const common = require('./category-definitions/common/index.json');
const fs = require('fs');
const prettyJs = require('pretty-js');
const json2ts = require('json-schema-to-typescript');
const derefSchema = require('json-schema-deref-sync');

const categories = [
    'ADI2',
    'B',
    'BE',
    'C', 'CE', 'C1', 'C1E', 'CM', 'C1M', 'CEM', 'C1EM',
    'D', 'DE', 'D1', 'D1E', 'DM', 'D1M', 'DEM', 'D1EM',
    'F', 'G', 'H', 'K',
];
// standalone categories are categories that don't merge with the common schema
const standaloneCategories = ['AM1', 'AM2', 'CPC', 'ADI3'];

// Json styling config
const options = {
    indent: "\t",
    newline: "\r\n",
    quoteProperties: "true"
};

const cliArgument = process.argv[2];

// Clears and cleans the generated schemas/typescripts
if (cliArgument === 'clean') {
    deleteFileIfExists(`./categories/common/index.d.ts`);
    for (let category of categories) {
        deleteFileIfExists(`./categories/${category}/index.json`);
        deleteFileIfExists(`./categories/${category}/partial.d.ts`);
        // DO NOT DELETE THIS FILE IT HAS BEEN MODIFIED BY HAND
        // AND WILL NOT BE REGENERATED
        // deleteFileIfExists(`./categories/${category}/index.d.ts`);
    }
    console.log('All categories have been cleaned');
}

if (cliArgument === 'generate') {
    // Generate common typescript file
    generateTypescriptInterfaces(`./category-definitions/common/index.json`, `./categories/common/index.d.ts`);
    for (let category of categories) {
        const partialSchema = `./category-definitions/${category}/partial.json`;
        const combinedSchema = `./categories/${category}/index.json`;

        // Generate combined schemas
        generateCombinedSchema(partialSchema, combinedSchema);

        // Generate typescript files
        generateTypescriptInterfaces(partialSchema, `./categories/${category}/partial.d.ts`);
        // DO NOT REGENERATE THIS FILE. IT HAS BEEN MODIFIED BY HAND
        // generateTypescriptInterfaces(combinedSchema);
    }

    for (let category of standaloneCategories) {
        // dereference and copy across Cat partial.json files
        deReferenceJsonSchema(`./category-definitions/${category}/index.json`, `./categories/${category}/index.json`);
        // generate Cat typescript files (standalone)
        generateTypescriptInterfaces(`./category-definitions/${category}/index.json`, `./categories/${category}/index.d.ts`);
    }

    // copy common partial.json file across for consistency
    copyFile(`./category-definitions/common/index.json`, `./categories/common/index.json`);
    console.log('All categories have been generated');
}

function copyFile(source: string, destination: string) {
    fs.copyFile(source, destination, (err: NodeJS.ErrnoException | null) => {
        if (err) throw err;
    });
}

function generateCombinedSchema(partialSchemaLocation: string, combinedSchemaLocation: string) {
    const currentCategoryJson = require(partialSchemaLocation);
    currentCategoryJson['title'] = currentCategoryJson['title'].replace('Partial ', '');
    const combinedJsonObject = removeRefs(merge(common, currentCategoryJson));
    let combinedJsonString = JSON.stringify(combinedJsonObject);
    combinedJsonString = combinedJsonString.replace(/..\/common\/index.json/g, '');
    fs.writeFileSync(combinedSchemaLocation, prettyJs(combinedJsonString, options));
}

function generateTypescriptInterfaces(schemaLocation: string, saveToLocation: string) {
    json2ts.compileFromFile(schemaLocation, {
        unreachableDefinitions: true
    }).then((ts: string) => fs.writeFileSync(saveToLocation, ts))
}

function deleteFileIfExists(fileLocation: string) {
    try {
        fs.unlinkSync(fileLocation);
    } catch (e) {
        console.error(e);
    }
}

// Remove all $ref if they have siblings
function removeRefs(obj: any): any {
    const removeRefsFields = (obj: any) => {
        Object.keys(obj).forEach((key) => {
            const value = obj[key];
            if (key === '$ref' && Object.keys(obj).length > 1) delete obj[key];
            if (typeof value === 'object') removeRefsFields(value);
        });
        return obj;
    };
    return removeRefsFields(obj);
}

function deReferenceJsonSchema(sourcePath: string, targetPath: string): void {
    const originalSchema = require(sourcePath);
    const baseFolder = sourcePath.substring(0, sourcePath.lastIndexOf("/"));
    let deReferencedJsonSchema = derefSchema(originalSchema, {
        baseFolder: baseFolder,
    });

    let deReferencedSchema = prettyJs(JSON.stringify(deReferencedJsonSchema), options);

    fs.writeFile(targetPath, deReferencedSchema, 'utf8', (err: NodeJS.ErrnoException | null) => {
        if (err) {
            console.error(`unable to write to file ${targetPath}`);
        }
    })
}