Putting together all of the above, here is the high-level algorithm

in pseudocode of what `require()` does:

require(X) from module at path Y

1. If X is a core module,

a. return the core module

2. If no scope was found, return.

3. If the SCOPE/package.json "imports" is null or undefined, return.

4. let MATCH = PACKAGE_IMPORTS_RESOLVE(X, pathToFileurl("https://github.com/nodejs/node/commit/SCOPE"),

5. RESOLVE_ESM_MATCH(MATCH).

LOAD_PACKAGE_EXPORTS(X, DIR)

3. Parse DIR/NAME/package.json, and look for "exports" field.

4. If "exports" is null or undefined, return.

5. let MATCH = PACKAGE_EXPORTS_RESOLVE(pathToFileurl("https://github.com/nodejs/node/commit/DIR/NAME"), "." + SUBPATH,

6. RESOLVE_ESM_MATCH(MATCH)

LOAD_PACKAGE_SELF(X, DIR)

4. If the SCOPE/package.json "name" is not the first segment of X, return.

5. let MATCH = PACKAGE_EXPORTS_RESOLVE(pathToFileurl("https://github.com/nodejs/node/commit/SCOPE"),

"." + X.slice("name".length), `package.json` "exports", ["node", "require"])

6. RESOLVE_ESM_MATCH(MATCH)

RESOLVE_ESM_MATCH(MATCH)

a. LOAD_AS_FILE(RESOLVED_PATH)

b. LOAD_AS_DIRECTORY(RESOLVED_PATH)

5. THROW "not found"