From c767c02015ed3d35b2e8ee21f12fc0f836c0a9e5 Mon Sep 17 00:00:00 2001
From: Ben Newman <ben@apollographql.com>
Date: Thu, 18 Nov 2021 15:31:49 -0500
Subject: [PATCH] Normalize 'ts-invariant/process' again in
 config/resolveModuleIds.ts.

From @apollo/client@3.5.0 until my recent PR #9073 (v3.5.3),
non-relative imported module identifiers like 'ts-invariant/process'
were rewritten during the build process (during 'npm run resolve') to
include a specific module with a file extension (not a directory),
producing in this example 'ts-invariant/process/index.js'.

That rewriting was the wrong choice in general (for example, it would
rewrite 'graphql' to 'graphql/index.mjs'), so PR #9073 disabled it for
all non-relative imports.

However, the specific replacement of 'ts-invariant/process' with
'ts-invariant/process/index.js' is still useful to prevent the strange
webpack 5-specific error

  The request 'ts-invariant/process' failed to resolve only because it was resolved as fully specified

which apparently happens because the
[resolve.fullySpecified](https://webpack.js.org/configuration/module/#resolvefullyspecified)
option is true by default now, and 'ts-invariant/process/package.json'
is ignored, effectively forbidding directory-style imports like
'ts-invariant/process' when the package.json of the enclosing package
has `"type": "module"` (which became true in Apollo Client v3.5, thanks
to #8396). App developers could configure resolve.fullySpecified
explicitly false, but we (the Apollo Client team) prefer a general
workaround.
---
 config/resolveModuleIds.ts | 37 +++++++++++++++++++++++++++++++------
 1 file changed, 31 insertions(+), 6 deletions(-)

diff --git a/config/resolveModuleIds.ts b/config/resolveModuleIds.ts
index a63ed739f3f..f8798c654d1 100644
--- a/config/resolveModuleIds.ts
+++ b/config/resolveModuleIds.ts
@@ -3,6 +3,18 @@ import * as path from "path";
 import resolve from "resolve";
 import { distDir, eachFile, reparse, reprint } from './helpers';
 
+// The primary goal of the 'npm run resolve' script is to make ECMAScript
+// modules exposed by Apollo Client easier to consume natively in web browsers,
+// without bundling, and without help from package.json files. It accomplishes
+// this goal by rewriting internal ./ and ../ (relative) imports to refer to a
+// specific ESM module (not a directory), including its file extension. Because
+// of this limited goal, this script only touches ESM modules that have .js file
+// extensions, not .cjs CommonJS bundles.
+
+// A secondary goal of this script is to enforce that any module using the
+// __DEV__ global constant imports the @apollo/client/utilities/globals polyfill
+// module first.
+
 eachFile(distDir, (file, relPath) => new Promise((resolve, reject) => {
   fs.readFile(file, "utf8", (error, source) => {
     if (error) return reject(error);
@@ -83,12 +95,25 @@ class Transformer {
   }
 
   normalizeSourceString(file: string, source?: Node | null) {
-    if (source && n.StringLiteral.check(source) && this.isRelative(source.value)) {
-      try {
-        source.value = this.normalizeId(source.value, file);
-      } catch (error) {
-        console.error(`Failed to resolve ${source.value} in ${file} with error ${error}`);
-        process.exit(1);
+    if (source && n.StringLiteral.check(source)) {
+      // We mostly only worry about normalizing _relative_ module identifiers,
+      // which start with a ./ or ../ and refer to other modules within the
+      // @apollo/client package, but we also manually normalize one non-relative
+      // identifier, ts-invariant/process, to prevent webpack 5 errors
+      // containing the phrase "failed to resolve only because it was resolved
+      // as fully specified," referring to webpack's resolve.fullySpecified
+      // option, which is apparently now true by default when the enclosing
+      // package's package.json file has "type": "module" (which became true for
+      // Apollo Client in v3.5).
+      if (source.value.split("/", 2).join("/") === "ts-invariant/process") {
+        source.value = "ts-invariant/process/index.js";
+      } else if (this.isRelative(source.value)) {
+        try {
+          source.value = this.normalizeId(source.value, file);
+        } catch (error) {
+          console.error(`Failed to resolve ${source.value} in ${file} with error ${error}`);
+          process.exit(1);
+        }
       }
     }
   }