require doesn't resolve in the global cache dir if referrer is not in DENODIR

[nathanwhit]

The scenario is roughly as follows:

You're using the global resolver (no node_modules dir) and you have a config file

// playwright.config.js (located in your project dir)
import playwrightTest from "playwright/test"; // in import map (there is no package.json)

Playwright (which is in the global cache dir) adds a hook that gets called right before the builtin require, then requires your config file (require(userConfigFilePath)).

Playwright's require hook transpiles your config file to CJS, which results in

// transpiled playwright.config.js ("located" in user's project dir)
const playwrightTest = require("playwright/test");

then calls deno's actual require function.

When deno hits require("playwright/test"); it searches relative to the config file (but no matches), then searches in "/node_modules", "/../node_modules" (etc.) but there are no matches, because the dependency is actually in the global cache dir.

Ideally we could handle this by resolving in the global cache dir instead of in the node_modules dirs (which don't exist or apply).

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Seen in #16899 (comment) (repro at https://github.com/jollytoad/ahx/tree/df1b391bb5adb51e879da17612570f7e7dd025f7)