[INTERNAL] Extract compile from index.js

Author: matz3

lib/Compiler.js

@@ -0,0 +1,191 @@
+const path = require("path");
+const createParser = require("./less/parser");
+const clone = require("clone");
+
+// Plugins
+const ImportCollectorPlugin = require("./plugin/import-collector");
+const VariableCollectorPlugin = require("./plugin/variable-collector");
+const UrlCollector = require("./plugin/url-collector");
+
+class Compiler {
+	constructor({options, fileUtils, customFs}) {
+		this.options = options;
+		this.fileUtils = fileUtils;
+
+		// Stores mapping between "virtual" paths (used within LESS) and real filesystem paths.
+		// Only relevant when using the "rootPaths" option.
+		this.mFileMappings = {};
+
+		// Only use custom file handler when "rootPaths" or custom "fs" are used
+		if ((this.options.rootPaths && this.options.rootPaths.length > 0) || customFs) {
+			this.fnFileHandler = this.createFileHandler();
+		} else {
+			this.fnFileHandler = undefined;
+		}
+	}
+	createFileHandler() {
+		return async (file, currentFileInfo, handleDataAndCallCallback, callback) => {
+			try {
+				let pathname;
+
+				// support absolute paths such as "/resources/my/base.less"
+				if (path.posix.isAbsolute(file)) {
+					pathname = path.posix.normalize(file);
+				} else {
+					pathname = path.posix.join(currentFileInfo.currentDirectory, file);
+				}
+
+				const result = await this.fileUtils.readFile(pathname, this.options.rootPaths);
+				if (!result) {
+					// eslint-disable-next-line no-console
+					console.log("File not found: " + pathname);
+					callback({type: "File", message: "Could not find file at path '" + pathname + "'"});
+				} else {
+					try {
+						// Save import mapping to calculate full import paths later on
+						this.mFileMappings[currentFileInfo.rootFilename] =
+							this.mFileMappings[currentFileInfo.rootFilename] || {};
+						this.mFileMappings[currentFileInfo.rootFilename][pathname] = result.path;
+
+						handleDataAndCallCallback(pathname, result.content);
+					} catch (e) {
+						// eslint-disable-next-line no-console
+						console.log(e);
+						callback(e);
+					}
+				}
+			} catch (err) {
+				// eslint-disable-next-line no-console
+				console.log(err);
+				callback(err);
+			}
+		};
+	}
+	async compile(config) {
+		const parserOptions = clone(this.options.parser);
+		let rootpath;
+
+		if (config.path) {
+			// Keep rootpath for later usage in the ImportCollectorPlugin
+			rootpath = config.path;
+			parserOptions.filename = config.localPath;
+		}
+
+		// inject the library name as prefix (e.g. "sap.m" as "_sap_m")
+		if (this.options.library && typeof this.options.library.name === "string") {
+			const libName = config.libName = this.options.library.name;
+			config.libPath = libName.replace(/\./g, "/");
+			config.prefix = "_" + libName.replace(/\./g, "_") + "_";
+		} else {
+			config.prefix = ""; // no library, no prefix
+		}
+
+		// Keep filename for later usage (see ImportCollectorPlugin) as less modifies the parserOptions.filename
+		const filename = parserOptions.filename;
+
+		const parser = createParser(parserOptions, this.fnFileHandler);
+
+		function parseContent(content) {
+			return new Promise(function(resolve, reject) {
+				parser.parse(content, function(err, tree) {
+					if (err) {
+						reject(err);
+					} else {
+						resolve(tree);
+					}
+				});
+			});
+		}
+
+		const tree = await parseContent(config.content);
+		const result = {tree};
+
+		// plugins to collect imported files and variable values
+		const oImportCollector = new ImportCollectorPlugin({
+			importMappings: this.mFileMappings[filename]
+		});
+		const oVariableCollector = new VariableCollectorPlugin(this.options.compiler);
+		const oUrlCollector = new UrlCollector();
+
+		// render to css
+		result.css = tree.toCSS(Object.assign({}, this.options.compiler, {
+			plugins: [oImportCollector, oVariableCollector, oUrlCollector]
+		}));
+
+		// retrieve imported files
+		result.imports = oImportCollector.getImports();
+
+		// retrieve reduced set of variables
+		result.variables = oVariableCollector.getVariables(Object.keys(this.mFileMappings[filename] || {}));
+
+		// retrieve all variables
+		result.allVariables = oVariableCollector.getAllVariables();
+
+		// also compile rtl-version if requested
+		let oRTL;
+		if (this.options.rtl) {
+			const RTLPlugin = require("./plugin/rtl");
+			oRTL = new RTLPlugin();
+
+			const urls = oUrlCollector.getUrls();
+
+			const existingImgRtlUrls = (await Promise.all(
+				urls.map(async ({currentDirectory, relativeUrl}) => {
+					const relativeImgRtlUrl = RTLPlugin.getRtlImgUrl(relativeUrl);
+					if (relativeImgRtlUrl) {
+						const resolvedImgRtlUrl = path.posix.join(currentDirectory, relativeImgRtlUrl);
+						if (await this.fileUtils.findFile(resolvedImgRtlUrl, this.options.rootPaths)) {
+							return resolvedImgRtlUrl;
+						}
+					}
+				})
+			)).filter(Boolean);
+
+			oRTL.setExistingImgRtlPaths(existingImgRtlUrls);
+		}
+
+		if (oRTL) {
+			result.cssRtl = tree.toCSS(Object.assign({}, this.options.compiler, {
+				plugins: [oRTL]
+			}));
+		}
+
+		if (rootpath) {
+			result.imports.unshift(rootpath);
+		}
+
+		// also compile css-variables version if requested
+		if (this.options.cssVariables) {
+			// parse the content again to have a clean tree
+			const cssVariablesSkeletonTree = await parseContent(config.content);
+
+			// generate the skeleton-css and the less-variables
+			const CSSVariablesCollectorPlugin = require("./plugin/css-variables-collector");
+			const oCSSVariablesCollector = new CSSVariablesCollectorPlugin(config);
+			const oVariableCollector = new VariableCollectorPlugin(this.options.compiler);
+			result.cssSkeleton = cssVariablesSkeletonTree.toCSS(Object.assign({}, this.options.compiler, {
+				plugins: [oCSSVariablesCollector, oVariableCollector]
+			}));
+			const varsOverride = oVariableCollector.getAllVariables();
+			result.cssVariablesSource = oCSSVariablesCollector.toLessVariables(varsOverride);
+
+			if (oRTL) {
+				const oCSSVariablesCollectorRTL = new CSSVariablesCollectorPlugin(config);
+				result.cssSkeletonRtl = cssVariablesSkeletonTree.toCSS(Object.assign({}, this.options.compiler, {
+					plugins: [oCSSVariablesCollectorRTL, oRTL]
+				}));
+			}
+
+			// generate the css-variables content out of the less-variables
+			const cssVariablesTree = await parseContent(result.cssVariablesSource);
+			const CSSVariablesPointerPlugin = require("./plugin/css-variables-pointer");
+			result.cssVariables = cssVariablesTree.toCSS(Object.assign({}, this.options.compiler, {
+				plugins: [new CSSVariablesPointerPlugin()]
+			}));
+		}
+
+		return result;
+	}
+}
+
+module.exports = Compiler;