class Opal::SourceMap::Index

Attributes

source_maps[R]

Public Class Methods

new(source_maps, join: nil) click to toggle source

@param source_maps [Opal::SourceMap::File] @param join: the string used to join the sources, empty by default, Opal::Builder uses “n”

# File lib/opal/source_map/index.rb, line 10
def initialize(source_maps, join: nil)
  @source_maps = source_maps
  @join = join
end

Public Instance Methods

map() click to toggle source

To support concatenating generated code and other common post processing, an alternate representation of a map is supported:

1: {
2: version : 3,
3: file: “app.js”,
4: sections: [
5:  { offset: {line:0, column:0}, url: “url_for_part1.map” }
6:  { offset: {line:100, column:10}, map:
7:    {
8:      version : 3,
9:      file: “section.js”,

10: sources: [“foo.js”, “bar.js”], 11: names: [“src”, “maps”, “are”, “fun”], 12: mappings: “AAAA,E;;ABCDE;” 13: } 14: } 15: ], 16: }

The index map follow the form of the standard map

Line 1: The entire file is an JSON object. Line 2: The version field. See the description of the standard map. Line 3: The name field. See the description of the standard map. Line 4: The sections field.

The “sections” field is an array of JSON objects that itself has two fields “offset” and a source map reference. “offset” is an object with two fields, “line” and “column”, that represent the offset into generated code that the referenced source map represents.

The other field must be either “url” or “map”. A “url” entry must be a URL where a source map can be found for this section and the url is resolved in the same way as the “sources” fields in the standard map. A “map” entry must be an embedded complete source map object. An embedded map does not inherit any values from the containing index map.

The sections must be sorted by starting position and the represented sections may not overlap.

# File lib/opal/source_map/index.rb, line 56
def map
  offset_line = 0
  offset_column = 0
  {
    version: 3,
    # file: "app.js",
    sections: @source_maps.map do |source_map|
      map = {
        offset: {
          line: offset_line,
          column: offset_column,
        },
        map: source_map.to_h,
      }

      generated_code  = source_map.generated_code
      generated_code += @join if @join
      new_lines_count = generated_code.count("\n")
      last_line       = generated_code[generated_code.rindex("\n") + 1..-1]

      offset_line    += new_lines_count
      offset_column  += last_line.size

      map
    end
  }
end