Algoritmo de Búsqueda Ejecutado por require

require(X) from module at path Y

1. If X is a core module,
   1. return the core module
   2. STOP
2. If X begins with './' or '/' or '../'
   1. LOAD_AS_FILE(Y + X)
   2. LOAD_AS_DIRECTORY(Y + X)
3. LOAD_NODE_MODULES(X, dirname(Y))
4. THROW "not found"

LOAD_AS_FILE(X)

1. If X is a file, load X as JavaScript text. STOP
2. If X.js is a file, load X.js as JavaScript text. STOP
3. If X.node is a file, load X.node as binary addon. STOP

LOAD_AS_DIRECTORY(X)

1. If X/package.json is a file, a. Parse X/package.json, and look for "main" field. b. let M = X + (json main field) c. LOAD_AS_FILE(M)
2. If X/index.js is a file, load X/index.js as JavaScript text. STOP
3. If X/index.node is a file, load X/index.node as binary addon. STOP

LOAD_NODE_MODULES(X, START)

1. let DIRS=NODE_MODULES_PATHS(START)
2. for each DIR in DIRS: a. LOAD_AS_FILE(DIR/X) b. LOAD_AS_DIRECTORY(DIR/X)

NODE_MODULES_PATHS(START)

1. let PARTS = path split(START)
2. let ROOT = index of first instance of "node_modules" in PARTS, or 0
3. let I = count of PARTS - 1
4. let DIRS = []
5. while I > ROOT, a. if PARTS[I] = "node_modules" CONTINUE c. DIR = path join(PARTS[0 .. I] + "node_modules") b. DIRS = DIRS + DIR c. let I = I - 1
6. return DIRS