Package com.google.javascript.jscomp

Class InjectTranspilationRuntimeLibraries

java.lang.Object
com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback
com.google.javascript.jscomp.InjectTranspilationRuntimeLibraries
All Implemented Interfaces:
CompilerPass, NodeTraversal.Callback
public final class InjectTranspilationRuntimeLibraries extends NodeTraversal.AbstractPostOrderCallback implements CompilerPass
Injects JS library code that may be needed by the transpiled form of the input source code.

The intention here is to add anything that could be needed and rely on RemoveUnusedCode to remove the parts that don't end up getting used. This pass should run before type checking so the type checking code can add type information to the injected JavaScript for checking and optimization purposes.

This class also reports an error if it finds getters or setters are used and the language output level is too low to support them. TODO(bradfordcsmith): The getter/setter check should probably be done separately in an earlier pass that only runs when the output language level is ES3 and the input language level is ES5 or greater.

TODO(b/120486392): consider merging this pass with InjectRuntimeLibraries and RewritePolyfills.

  • Constructor Details

    • InjectTranspilationRuntimeLibraries

      public InjectTranspilationRuntimeLibraries(AbstractCompiler 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

    • visit

      public void visit(NodeTraversal t, Node n, Node parent)
      Description copied from interface: NodeTraversal.Callback
      Visits a node in postorder (after its children). A node is visited in postorder iff NodeTraversal.Callback.shouldTraverse(NodeTraversal, Node, Node) returned true for its parent and itself. In particular, the root node is never visited in postorder.

      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:
      visit in interface NodeTraversal.Callback
      Parameters:
      t - The current traversal.
      n - The current node.
      parent - The parent of the current node.