Source Map Generation

/**
 * Creates a new source map generator
 * @param args - Configuration options for the source map
 */
class SourceMapGenerator {
  constructor(args?: StartOfSourceMap);
  
  /**
   * Creates a new SourceMapGenerator based on a SourceMapConsumer
   * @param sourceMapConsumer - The source map to convert
   */
  static fromSourceMap(sourceMapConsumer: SourceMapConsumer): SourceMapGenerator;
  
  /**
   * Add a single mapping from original source line and column to the generated
   * source's line and column for this source map being created
   * @param mapping - The mapping object containing position information
   */
  addMapping(mapping: Mapping): void;
  
  /**
   * Set the source content for a source file
   * @param sourceFile - The filename of the original source
   * @param sourceContent - The content of the original source file
   */
  setSourceContent(sourceFile: string, sourceContent: string): void;
  
  /**
   * Applies the mappings of a sub-source-map for a specific source file to the
   * source map being generated. Each mapping to the supplied source file is
   * rewritten using the supplied source map.
   * @param sourceMapConsumer - The source map to be applied
   * @param sourceFile - Optional filename of the source file
   * @param sourceMapPath - Optional dirname of the path to the source map
   */
  applySourceMap(
    sourceMapConsumer: SourceMapConsumer,
    sourceFile?: string,
    sourceMapPath?: string
  ): void;
  
  /**
   * Render the source map as a JSON string
   */
  toString(): string;
  
  /**
   * Export the source map as a raw object
   */
  toJSON(): RawSourceMap;
}

interface StartOfSourceMap {
  /** The filename of the generated source */
  file?: string;
  /** A root for all relative URLs in this source map */
  sourceRoot?: string;
  /** Skip validation of mappings */
  skipValidation?: boolean;
}

interface Mapping {
  /** An object with the generated line and column positions */
  generated: Position;
  /** An object with the original line and column positions */
  original: Position;
  /** The original source file (relative to the sourceRoot) */
  source: string;
  /** An optional original token name for this mapping */
  name?: string;
}

interface Position {
  line: number;   // 1-based line number
  column: number; // 0-based column number
}

interface RawSourceMap {
  version: number;
  sources: string[];
  names: string[];
  sourceRoot?: string;
  sourcesContent?: string[];
  mappings: string;
  file: string;
}

import { SourceMapGenerator } from "source-map";

// Create a new source map
const map = new SourceMapGenerator({
  file: "bundled.js",
  sourceRoot: "http://example.com/"
});

// Add mappings during code generation
map.addMapping({
  generated: { line: 1, column: 0 },
  source: "input.js",
  original: { line: 1, column: 0 }
});

map.addMapping({
  generated: { line: 1, column: 18 },
  source: "input.js", 
  original: { line: 1, column: 11 },
  name: "add"
});

// Set source content
map.setSourceContent("input.js", "function add(a,b){return a+b}");

// Generate the source map
const sourceMapJSON = map.toString();
console.log(sourceMapJSON);

interface StartOfSourceMap {
  /** The filename of the generated source */
  file?: string;
  /** A root for all relative URLs in this source map */
  sourceRoot?: string;
  /** Skip validation of mappings */
  skipValidation?: boolean;
}

const generator = new SourceMapGenerator({
  file: "output.js",              // Generated file name  
  sourceRoot: "/project/src/",    // Base path for source files
  skipValidation: false           // Enable mapping validation (default)
});

/**
 * Add a single mapping from original source line and column to the generated
 * source's line and column for this source map being created
 */
addMapping(mapping: Mapping): void;

interface Mapping {
  generated: Position;  // Required: position in generated code
  original: Position;   // Required: position in original code
  source: string;       // Required: original source file name
  name?: string;        // Optional: original identifier name
}

// Basic mapping
map.addMapping({
  generated: { line: 10, column: 5 },
  original: { line: 20, column: 15 },
  source: "original.js"
});

// Mapping with identifier name
map.addMapping({
  generated: { line: 15, column: 8 },
  original: { line: 25, column: 12 },
  source: "original.js",
  name: "functionName"
});

/**
 * Set the source content for a source file
 * @param sourceFile - The filename of the original source
 * @param sourceContent - The content of the original source file
 */
setSourceContent(sourceFile: string, sourceContent: string): void;

// Set content for debugging
map.setSourceContent("math.js", `
function add(a, b) {
  return a + b;
}
`);

map.setSourceContent("utils.js", `
export function format(value) {
  return String(value);
}
`);

/**
 * Applies the mappings of a sub-source-map for a specific source file
 * @param sourceMapConsumer - The source map to be applied
 * @param sourceFile - Optional filename of the source file
 * @param sourceMapPath - Optional dirname of the path to the source map
 */
applySourceMap(
  sourceMapConsumer: SourceMapConsumer,
  sourceFile?: string,
  sourceMapPath?: string
): void;

import { SourceMapConsumer, SourceMapGenerator } from "source-map";

// Apply TypeScript -> JavaScript source map to JavaScript -> minified map
const tsToJsMap = await new SourceMapConsumer(typescriptSourceMap);
const jsToMinMap = new SourceMapGenerator({ file: "output.min.js" });

// This creates a direct TypeScript -> minified mapping
jsToMinMap.applySourceMap(tsToJsMap, "intermediate.js");

/**
 * Creates a new SourceMapGenerator based on a SourceMapConsumer
 * @param sourceMapConsumer - The source map to convert
 */
static fromSourceMap(sourceMapConsumer: SourceMapConsumer): SourceMapGenerator;

// Load existing source map
const consumer = await new SourceMapConsumer(existingSourceMap);

// Convert to generator for modification
const generator = SourceMapGenerator.fromSourceMap(consumer);

// Add additional mappings
generator.addMapping({
  generated: { line: 100, column: 0 },
  original: { line: 50, column: 10 },
  source: "new-file.js"
});

// Clean up consumer
consumer.destroy();

/**
 * Render the source map as a JSON string
 */
toString(): string;

/**
 * Export the source map as a raw object
 */
toJSON(): RawSourceMap;

// Get as JSON string for embedding
const jsonString = generator.toString();
console.log(jsonString);
// Output: {"version":3,"sources":["input.js"],"names":[],"mappings":"AAAA","file":"output.js"}

// Get as object for manipulation
const mapObject = generator.toJSON();
console.log(mapObject.sources);  // ["input.js"]
console.log(mapObject.version);  // 3

try {
  map.addMapping({
    generated: { line: 0, column: 5 },  // Invalid: line must be >= 1
    original: { line: 1, column: 0 },
    source: "test.js"
  });
} catch (error) {
  console.error("Invalid mapping:", error.message);
}