Class RewriteJsonToModule

  • All Implemented Interfaces:
    CompilerPass, NodeTraversal.Callback

    public class RewriteJsonToModule
    extends NodeTraversal.AbstractPostOrderCallback
    implements CompilerPass
    Rewrites a JSON file to be a module export. So that the JSON file parses correctly, it is wrapped in an EXPR_RESULT. The pass makes only basic checks that the file provided is valid JSON. It is not a full JSON validator.

    Looks for JSON files named "package.json" so that the "main" property can be used as an alias in module name resolution. See https://docs.npmjs.com/files/package.json#main

    • Field Detail

      • JSON_UNEXPECTED_TOKEN

        public static final DiagnosticType JSON_UNEXPECTED_TOKEN
    • Constructor Detail

      • RewriteJsonToModule

        public RewriteJsonToModule​(AbstractCompiler compiler)
        Creates a new RewriteJsonToModule instance which can be used to rewrite JSON files to modules.
        Parameters:
        compiler - The compiler
    • Method Detail

      • getPackageJsonMainEntries

        public com.google.common.collect.ImmutableMap<java.lang.String,​java.lang.String> getPackageJsonMainEntries()
      • process

        public void process​(Node externs,
                            Node root)
        Module rewriting is done a on per-file basis prior to main compilation. The root node for each file is a SCRIPT - not the typical jsRoot of other passes.
        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. 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.