Configuration

Blanket.js configuration system for controlling coverage behavior, file filtering, and output options.

Capabilities

Options Method

Central configuration method for getting and setting all Blanket.js options.

/**
 * Get or set configuration options
 * @param key - Option key (string) or options object
 * @param value - Option value (when key is string)
 * @returns Option value (when used as getter), undefined (when used as setter)
 */
function options(key, value);

Usage Examples:

// Set single option
blanket.options("filter", "src/");

// Set multiple options
blanket.options({
  filter: "src/",
  antifilter: "test/",
  debug: true
});

// Get option value
const currentFilter = blanket.options("filter");

Utility Methods

/**
 * Get the coverage variable name
 * @returns Coverage variable name ("window._$blanket" in browser, "_$jscoverage" in Node.js, or custom)
 */
function getCovVar();

/**
 * Extend blanket object with additional properties/methods
 * @param obj - Object with properties to add to blanket
 */
function extend(obj);

/**
 * Return control of the blanket variable to previous owner
 * @returns Previous blanket instance or current instance
 */
function noConflict();

Configuration Options

File Filtering Options

filter - Pattern to match files for instrumentation

• Type: string | string[] | RegExp | Function
• Default: "src"
• Examples:

  // String pattern (substring match)
  blanket.options("filter", "src/");
  
  // Array of patterns
  blanket.options("filter", ["src/", "lib/"]);
  
  // Regular expression
  blanket.options("filter", /^src\//);
  
  // Function
  blanket.options("filter", function(filename) {
    return filename.indexOf("src/") >= 0;
  });

antifilter - Pattern to exclude files from instrumentation

• Type: string | string[] | RegExp | Function
• Default: undefined
• Description: Files matching this pattern will never be instrumented, even if they match the filter

Reporter Options

reporter - Coverage report output handler

• Type: string | Function
• Default: Built-in HTML reporter (browser) or console reporter (Node.js)
• Examples:

  // Path to custom reporter
  blanket.options("reporter", "./custom-reporter.js");
  
  // Custom reporter function
  blanket.options("reporter", function(coverageData) {
    console.log("Coverage:", coverageData);
  });

reporter_options - Options passed to reporters

• Type: object
• Properties:
  • shortnames (boolean): Use short filenames in reports
  • relativepath (boolean): Use relative paths from current directory
  • basepath (string): Base path to remove from filenames

Test Framework Integration

adapter - Test framework adapter

• Type: string
• Examples: "mocha-blanket", "jasmine-blanket", "qunit-blanket"

testReadyCallback - Callback when tests are ready to run

• Type: Function
• Description: Called when all files are instrumented and ready for testing

File Loading Options

loader - Custom file loaders for different file types

• Type: string | string[]
• Examples:

  // Single loader
  blanket.options("loader", "./node-loaders/coffee-script");
  
  // Multiple loaders
  blanket.options("loader", [
    "./node-loaders/coffee-script",
    "./node-loaders/cjsx"
  ]);

timeout - File loading timeout in milliseconds

• Type: number
• Default: 180

Behavioral Flags

ignoreScriptError - Continue on script instrumentation errors

• Type: boolean
• Default: false
• Description: When true, continues execution if a file fails to instrument

autoStart - Automatically start test runner

• Type: boolean
• Default: false

branchTracking - Enable branch coverage tracking

• Type: boolean
• Default: false
• Description: Tracks which branches of conditional statements are executed

debug - Enable debug logging

• Type: boolean
• Default: false
• Description: Outputs detailed logging to console during instrumentation

engineOnly - Instrumentation engine only mode

• Type: boolean
• Default: false
• Description: Only provides instrumentation engine without require.extensions integration

commonJS - CommonJS module support

• Type: boolean
• Default: false

Browser-Specific Options

existingRequireJS - Use existing RequireJS instance

• Type: boolean
• Default: false

ignoreCors - Ignore CORS errors when loading files

• Type: boolean
• Default: false

sourceURL - Add sourceURL comments to instrumented code

• Type: boolean
• Default: false

instrumentCache - Cache instrumented files in sessionStorage

• Type: boolean
• Default: false

Advanced Options

customVariable - Custom coverage variable name

• Type: string
• Default: undefined
• Description: Override default coverage variable (_$blanket or _$jscoverage)

modulePattern - Pattern for module grouping in reports

• Type: RegExp
• Description: Groups related files together in coverage reports

ecmaVersion - ECMAScript version for parsing

• Type: number
• Default: 5
• Description: ECMAScript version passed to the Esprima parser

Package.json Configuration

Blanket.js can also be configured via package.json:

{
  "config": {
    "blanket": {
      "pattern": "src/",
      "data-cover-flags": {
        "debug": false,
        "branchTracking": true
      },
      "data-cover-reporter-options": {
        "shortnames": true
      }
    }
  }
}

Configuration keys in package.json:

• pattern or data-cover-only → filter option
• data-cover-never → antifilter option
• loader or data-cover-loader → loader option
• data-cover-timeout → timeout option
• data-cover-customVariable → customVariable option
• data-cover-ecmaVersion → ecmaVersion option
• data-cover-flags → various boolean flags
• data-cover-reporter-options → reporter_options object