using pnpify to fix typescript module resolution

pnpify.js

@@ -0,0 +1,58 @@
+let pnp;
+try {
+  // If we're in PnP, run pnpify so typescript thinks it's fetching 
+  // absolute imports from node_modules/ rather than the yarn cache.
+  pnp = require(`pnpapi`);
+  const pnpify = require(`@yarnpkg/pnpify`);
+  pnpify.patchFs();
+} catch (error) {
+  // not in PnP; not a problem
+}
+
+function resolveModuleName(request, issuer, compilerOptions, moduleResolutionHost, parentResolver) {
+
+  const topLevelLocation = pnp.getPackageInformation(pnp.topLevel).packageLocation;
+
+  const [, prefix = ``, packageName = ``, rest] = request.match(/^(!(?:.*!)+)?((?!\.{0,2}\/)(?:@[^\/]+\/)?[^\/]+)?(.*)/);
+
+
+  let failedLookupLocations = [];
+
+  // First we try the resolution on "@types/package-name" starting from the project root
+  if (packageName) {
+    const typesPackagePath = `@types/${packageName.replace(/\//g, `__`)}${rest}`;
+
+    const finalResolution = parentResolver(typesPackagePath, issuer, compilerOptions, moduleResolutionHost);
+
+    if (finalResolution.resolvedModule || finalResolution.resolvedTypeReferenceDirective) {
+      return finalResolution;
+    } else {
+      failedLookupLocations = failedLookupLocations.concat(finalResolution.failedLookupLocations);
+    }
+  }
+
+  // Then we try on "package-name", this time starting from the package that makes the request
+  if (true) {
+    const regularPackagePath = `${packageName || ``}${rest}`;
+
+    const finalResolution = parentResolver(regularPackagePath, issuer, compilerOptions, moduleResolutionHost);
+
+    if (finalResolution.resolvedModule || finalResolution.resolvedTypeReferenceDirective) {
+      return finalResolution;
+    } else {
+      failedLookupLocations = failedLookupLocations.concat(finalResolution.failedLookupLocations);
+    }
+  }
+
+  return {
+    resolvedModule: undefined,
+    resolvedTypeReferenceDirective: undefined,
+    failedLookupLocations,
+  };
+}
+
+module.exports.resolveModuleName = pnp
+  ? resolveModuleName
+  : (moduleName, containingFile, compilerOptions, compilerHost, resolveModuleName) =>
+      resolveModuleName(moduleName, containingFile, compilerOptions, compilerHost);
+