def compute_module_name(testonly):
    """ Provide better defaults for package names.

    e.g. rather than angular/packages/core/testing we want @angular/core/testing
    """
    pkg = native.package_name()

    if testonly:
        # Some tests currently rely on the long-form package names
        return None

    if pkg.startswith("packages/bazel"):
        # Avoid infinite recursion in the ViewEngine compiler. Error looks like:
        #  Compiling Angular templates (ngc) //packages/bazel/test/ngc-wrapped/empty:empty failed (Exit 1)
        # : RangeError: Maximum call stack size exceeded
        #    at normalizeString (path.js:57:25)
        #    at Object.normalize (path.js:1132:12)
        #    at Object.join (path.js:1167:18)
        #    at resolveModule (execroot/angular/bazel-out/host/bin/packages/bazel/src/ngc-wrapped/ngc-wrapped.runfiles/angular/packages/compiler-cli/src/metadata/bundler.js:582:50)
        #    at MetadataBundler.exportAll (execroot/angular/bazel-out/host/bin/packages/bazel/src/ngc-wrapped/ngc-wrapped.runfiles/angular/packages/compiler-cli/src/metadata/bundler.js:119:42)
        #    at MetadataBundler.exportAll (execroot/angular/bazel-out/host/bin/packages/bazel/src/ngc-wrapped/ngc-wrapped.runfiles/angular/packages/compiler-cli/src/metadata/bundler.js:121:52)
        return None

    if pkg.startswith("packages/"):
        return "@angular/" + pkg[len("packages/"):]

    return None