Package com.google.javascript.jscomp

Class ProcessCommonJSModules

java.lang.Object

com.google.javascript.jscomp.NodeTraversal.AbstractPreOrderCallback

com.google.javascript.jscomp.ProcessCommonJSModules

All Implemented Interfaces:

CompilerPass, NodeTraversal.Callback

public final class ProcessCommonJSModules
extends NodeTraversal.AbstractPreOrderCallback
implements CompilerPass

Rewrites a CommonJS module http://wiki.commonjs.org/wiki/Modules/1.1.1 into a form that can be safely concatenated. Does not add a function around the module body but instead adds suffixes to global variables to avoid conflicts. Calls to require are changed to reference the required module directly.

Field Summary

Fields

Modifier and Type	Field	Description
static final DiagnosticType	SUSPICIOUS_EXPORTS_ASSIGNMENT
static final DiagnosticType	UNKNOWN_REQUIRE_ENSURE

Constructor Summary

Constructors

Constructor	Description
ProcessCommonJSModules(AbstractCompiler compiler)	Creates a new ProcessCommonJSModules instance which can be used to rewrite CommonJS modules to a concatenable form.

Method Summary

Modifier and Type	Method	Description
String	getBasePropertyImport(String moduleName)
String	getCommonJsImportPath(Node requireCall)
static String	getCommonJsImportPath(Node requireCall, ModuleLoader.ResolutionMode resolutionMode)
static @Nullable String	getModuleName(CompilerInput input)
static String	getModuleName(ModuleLoader.ModulePath input)
static boolean	isCommonJsDynamicImportCallback(Node n, ModuleLoader.ResolutionMode resolutionMode)	Recognize if a node is a dynamic module import.
static boolean	isCommonJsExport(NodeTraversal t, Node export, ModuleLoader.ResolutionMode resolutionMode)	Recognize if a node is a module export.
boolean	isCommonJsImport(Node requireCall)
static boolean	isCommonJsImport(Node requireCall, ModuleLoader.ResolutionMode resolutionMode)	Recognize if a node is a module import.
void	process(Node externs, Node root)	Process the JS with root node root.
boolean	shouldTraverse(NodeTraversal t, Node n, Node parent)	Visits a node in preorder (before its children) and decides whether the node and its children should be traversed.

Methods inherited from class com.google.javascript.jscomp.NodeTraversal.AbstractPreOrderCallback

visit

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

UNKNOWN_REQUIRE_ENSURE

public static final DiagnosticType UNKNOWN_REQUIRE_ENSURE

SUSPICIOUS_EXPORTS_ASSIGNMENT

public static final DiagnosticType SUSPICIOUS_EXPORTS_ASSIGNMENT

Constructor Details

ProcessCommonJSModules

public ProcessCommonJSModules(AbstractCompiler compiler)

Creates a new ProcessCommonJSModules instance which can be used to rewrite CommonJS modules to a concatenable form.

Parameters:

compiler - The compiler

Method Details

process

public void process(Node externs,
 Node root)

Description copied from interface: CompilerPass

Process the JS with root node root. Can modify the contents of each Node tree

Specified by:

process in interface CompilerPass

Parameters:

externs - Top of external JS tree

root - Top of JS tree

shouldTraverse

public boolean shouldTraverse(NodeTraversal t,
 Node n,
 Node parent)

Description copied from interface: NodeTraversal.Callback

Visits a node in preorder (before its children) and decides whether the node and its children should be traversed.

If this method returns true, the node will be visited by NodeTraversal.Callback.visit(NodeTraversal, Node, Node) in postorder and its children will be visited by both NodeTraversal.Callback.shouldTraverse(NodeTraversal, Node, Node) in preorder and by NodeTraversal.Callback.visit(NodeTraversal, Node, Node) in postorder.

If this method returns false, the node will not be visited by NodeTraversal.Callback.visit(NodeTraversal, Node, Node) and its children will neither be visited by NodeTraversal.Callback.shouldTraverse(NodeTraversal, Node, Node) nor NodeTraversal.Callback.visit(NodeTraversal, Node, Node).

Siblings are always visited left-to-right.

Implementations can have side-effects (e.g. modify the parse tree). Removing the current node is legal, but removing or reordering nodes above the current node may cause nodes to be visited twice or not at all.

Specified by:

shouldTraverse in interface NodeTraversal.Callback

Parameters:

t - The current traversal.

n - The current node.

parent - The parent of the current node.

Returns:

whether the children of this node should be visited

getModuleName

public static @Nullable String getModuleName(CompilerInput input)

getModuleName

public static String getModuleName(ModuleLoader.ModulePath input)

getBasePropertyImport

public String getBasePropertyImport(String moduleName)

isCommonJsImport

public boolean isCommonJsImport(Node requireCall)

isCommonJsImport

public static boolean isCommonJsImport(Node requireCall,
 ModuleLoader.ResolutionMode resolutionMode)

Recognize if a node is a module import. We recognize two forms:

• require("something");
• __webpack_require__(4); // only when the module resolution is WEBPACK
• __webpack_require__.t(4); // only when the module resolution is WEBPACK

getCommonJsImportPath

public String getCommonJsImportPath(Node requireCall)

getCommonJsImportPath

public static String getCommonJsImportPath(Node requireCall,
 ModuleLoader.ResolutionMode resolutionMode)

isCommonJsExport

public static boolean isCommonJsExport(NodeTraversal t,
 Node export,
 ModuleLoader.ResolutionMode resolutionMode)

Recognize if a node is a module export. We recognize several forms:

• module.exports = something;
• module.exports.something = something;
• exports.something = something;

In addition, we only recognize an export if the base export object is not defined or is defined in externs.

isCommonJsDynamicImportCallback

public static boolean isCommonJsDynamicImportCallback(Node n,
 ModuleLoader.ResolutionMode resolutionMode)

Recognize if a node is a dynamic module import. Currently only the webpack dynamic import is recognized:

• __webpack_require__.e(0).then(function() { return __webpack_require__(4);})
• Promise.all([__webpack_require__.e(0)]).then(function() { return __webpack_require__(4);})