@sap/cds-dk/lib/util/fs.js

Command line client and development toolkit for the SAP Cloud Application Programming Model

const { read, write, yaml: YAML } = require('../cds').utils
const JSONC = require('./jsonc');

// REVISIT: Consider merging with template util

module.exports = new class FsUtil {

    constructor() {
        this.copyRenderedJSON = this.copyRenderedJSON.bind(this)
        this.copyRenderedYAML = this.copyRenderedYAML.bind(this)
    }

    async readYAML(src, project) {
        let file
        try {
            file = await read(src, 'utf8')
        } catch (e) {
            if (e.code === 'ENOENT') return undefined
            throw e
        }
        if (project) {
            const Mustache = require('mustache')
            const renderedFile = Mustache.render(file, project)
            return YAML.parseDocument(renderedFile)
        }
        return YAML.parseDocument(file)
    }

    async writeYAML(dst, yaml) {
        const content = YAML.stringify(yaml, { collectionStyle: 'block', lineWidth: 150, directives: false })
        await write(content).to(dst)
    }

    async copyRenderedYAML(src, dst, project) {
        const yaml = await this.readYAML(src, project)
        await write(yaml.toString()).to(dst)
    }

    async readJSON(src, project) {
        const file = await read(src, 'utf8')
        if (project) {
            const Mustache = require('mustache')
            const renderedFile = Mustache.render(file, project)
            return JSON.parse(renderedFile)
        }
        try {
            return JSON.parse(file)
        } catch (error) {
            throw new Error(error.message + '\n' + file)
        }
    }

    async readJSONC(src) {
        return JSONC.parse(await read(src, 'utf8'))
    }

    async copyRenderedJSON(src, dst, project) {
        const json = await this.readJSON(src, project)
        await write(dst, json, { spaces: 2 })
    }
}