webpack/lib/dependencies/AMDRequireDependenciesBlockParserPlugin.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
"use strict";

const AMDRequireItemDependency = require("./AMDRequireItemDependency");
const AMDRequireArrayDependency = require("./AMDRequireArrayDependency");
const AMDRequireContextDependency = require("./AMDRequireContextDependency");
const AMDRequireDependenciesBlock = require("./AMDRequireDependenciesBlock");
const UnsupportedDependency = require("./UnsupportedDependency");
const LocalModuleDependency = require("./LocalModuleDependency");
const ContextDependencyHelpers = require("./ContextDependencyHelpers");
const LocalModulesHelpers = require("./LocalModulesHelpers");
const ConstDependency = require("./ConstDependency");
const getFunctionExpression = require("./getFunctionExpression");
const UnsupportedFeatureWarning = require("../UnsupportedFeatureWarning");

class AMDRequireDependenciesBlockParserPlugin {
	constructor(options) {
		this.options = options;
	}

	processFunctionArgument(parser, expression) {
		let bindThis = true;
		const fnData = getFunctionExpression(expression);
		if (fnData) {
			parser.inScope(
				fnData.fn.params.filter(i => {
					return !["require", "module", "exports"].includes(i.name);
				}),
				() => {
					if (fnData.fn.body.type === "BlockStatement") {
						parser.walkStatement(fnData.fn.body);
					} else {
						parser.walkExpression(fnData.fn.body);
					}
				}
			);
			parser.walkExpressions(fnData.expressions);
			if (fnData.needThis === false) {
				bindThis = false;
			}
		} else {
			parser.walkExpression(expression);
		}
		return bindThis;
	}

	apply(parser) {
		parser.hooks.call
			.for("require")
			.tap(
				"AMDRequireDependenciesBlockParserPlugin",
				this.processCallRequire.bind(this, parser)
			);
	}

	processArray(parser, expr, param) {
		if (param.isArray()) {
			for (const p of param.items) {
				const result = this.processItem(parser, expr, p);
				if (result === undefined) {
					this.processContext(parser, expr, p);
				}
			}
			return true;
		} else if (param.isConstArray()) {
			const deps = [];
			for (const request of param.array) {
				let dep, localModule;
				if (request === "require") {
					dep = "__webpack_require__";
				} else if (["exports", "module"].includes(request)) {
					dep = request;
				} else if (
					(localModule = LocalModulesHelpers.getLocalModule(
						parser.state,
						request
					))
				) {
					dep = new LocalModuleDependency(localModule, undefined, false);
					dep.loc = expr.loc;
					parser.state.current.addDependency(dep);
				} else {
					dep = this.newRequireItemDependency(request);
					dep.loc = expr.loc;
					dep.optional = !!parser.scope.inTry;
					parser.state.current.addDependency(dep);
				}
				deps.push(dep);
			}
			const dep = this.newRequireArrayDependency(deps, param.range);
			dep.loc = expr.loc;
			dep.optional = !!parser.scope.inTry;
			parser.state.current.addDependency(dep);
			return true;
		}
	}
	processItem(parser, expr, param) {
		if (param.isConditional()) {
			for (const p of param.options) {
				const result = this.processItem(parser, expr, p);
				if (result === undefined) {
					this.processContext(parser, expr, p);
				}
			}
			return true;
		} else if (param.isString()) {
			let dep, localModule;
			if (param.string === "require") {
				dep = new ConstDependency("__webpack_require__", param.string);
			} else if (param.string === "module") {
				dep = new ConstDependency(
					parser.state.module.buildInfo.moduleArgument,
					param.range
				);
			} else if (param.string === "exports") {
				dep = new ConstDependency(
					parser.state.module.buildInfo.exportsArgument,
					param.range
				);
			} else if (
				(localModule = LocalModulesHelpers.getLocalModule(
					parser.state,
					param.string
				))
			) {
				dep = new LocalModuleDependency(localModule, param.range, false);
			} else {
				dep = this.newRequireItemDependency(param.string, param.range);
			}
			dep.loc = expr.loc;
			dep.optional = !!parser.scope.inTry;
			parser.state.current.addDependency(dep);
			return true;
		}
	}
	processContext(parser, expr, param) {
		const dep = ContextDependencyHelpers.create(
			AMDRequireContextDependency,
			param.range,
			param,
			expr,
			this.options,
			{},
			parser
		);
		if (!dep) return;
		dep.loc = expr.loc;
		dep.optional = !!parser.scope.inTry;
		parser.state.current.addDependency(dep);
		return true;
	}

	processArrayForRequestString(param) {
		if (param.isArray()) {
			const result = param.items.map(item =>
				this.processItemForRequestString(item)
			);
			if (result.every(Boolean)) return result.join(" ");
		} else if (param.isConstArray()) {
			return param.array.join(" ");
		}
	}

	processItemForRequestString(param) {
		if (param.isConditional()) {
			const result = param.options.map(item =>
				this.processItemForRequestString(item)
			);
			if (result.every(Boolean)) return result.join("|");
		} else if (param.isString()) {
			return param.string;
		}
	}

	processCallRequire(parser, expr) {
		let param;
		let dep;
		let result;

		const old = parser.state.current;

		if (expr.arguments.length >= 1) {
			param = parser.evaluateExpression(expr.arguments[0]);
			dep = this.newRequireDependenciesBlock(
				expr,
				param.range,
				expr.arguments.length > 1 ? expr.arguments[1].range : null,
				expr.arguments.length > 2 ? expr.arguments[2].range : null,
				parser.state.module,
				expr.loc,
				this.processArrayForRequestString(param)
			);
			parser.state.current = dep;
		}

		if (expr.arguments.length === 1) {
			parser.inScope([], () => {
				result = this.processArray(parser, expr, param);
			});
			parser.state.current = old;
			if (!result) return;
			parser.state.current.addBlock(dep);
			return true;
		}

		if (expr.arguments.length === 2 || expr.arguments.length === 3) {
			try {
				parser.inScope([], () => {
					result = this.processArray(parser, expr, param);
				});
				if (!result) {
					dep = new UnsupportedDependency("unsupported", expr.range);
					old.addDependency(dep);
					if (parser.state.module) {
						parser.state.module.errors.push(
							new UnsupportedFeatureWarning(
								parser.state.module,
								"Cannot statically analyse 'require(…, …)' in line " +
									expr.loc.start.line,
								expr.loc
							)
						);
					}
					dep = null;
					return true;
				}
				dep.functionBindThis = this.processFunctionArgument(
					parser,
					expr.arguments[1]
				);
				if (expr.arguments.length === 3) {
					dep.errorCallbackBindThis = this.processFunctionArgument(
						parser,
						expr.arguments[2]
					);
				}
			} finally {
				parser.state.current = old;
				if (dep) parser.state.current.addBlock(dep);
			}
			return true;
		}
	}

	newRequireDependenciesBlock(
		expr,
		arrayRange,
		functionRange,
		errorCallbackRange,
		module,
		loc,
		request
	) {
		return new AMDRequireDependenciesBlock(
			expr,
			arrayRange,
			functionRange,
			errorCallbackRange,
			module,
			loc,
			request
		);
	}
	newRequireItemDependency(request, range) {
		return new AMDRequireItemDependency(request, range);
	}
	newRequireArrayDependency(depsArray, range) {
		return new AMDRequireArrayDependency(depsArray, range);
	}
}
module.exports = AMDRequireDependenciesBlockParserPlugin;