Fix source maps and simplify getApolloContext to avoid global symbols.

config/rewriteSourceMaps.ts

@@ -0,0 +1,44 @@
+import * as fs from "fs";
+import * as path from "path";
+import { distDir } from './helpers';
+import glob = require("glob");
+
+glob(`${distDir}/**/*.js.map`, (error, files) => {
+  if (error) throw error;
+
+  const rootDir = path.dirname(distDir);
+
+  const startTime = Date.now();
+  let rewriteCount = 0;
+
+  Promise.all(files.map(async file => {
+    const content = await fs.promises.readFile(file, "utf8");
+    const map = JSON.parse(content);
+    if (map.sourcesContent) return;
+    if (map.sources) {
+      map.sourcesContent = await Promise.all(
+        map.sources.map((relSourcePath: string) => {
+          const sourcePath = path.normalize(
+            path.join(path.dirname(file), relSourcePath));
+          const relPath = path.relative(rootDir, sourcePath);
+          // Disallow reading paths outside rootDir.
+          if (relPath.startsWith("../")) {
+            throw new Error(`Bad path: ${sourcePath}`);
+          }
+          return fs.promises.readFile(sourcePath, "utf8");
+        })
+      );
+      ++rewriteCount;
+      return fs.promises.writeFile(file, JSON.stringify(map));
+    }
+  })).then(() => {
+    console.log(`Rewrote ${
+      rewriteCount
+    } source maps in ${
+      Date.now() - startTime
+    }ms`);
+  }, error => {
+    console.error(error);
+    process.exit(-1);
+  });
+});

config/tsconfig.json

@@ -10,5 +10,14 @@
     "target": "es5",
     "module": "commonjs",
     "esModuleInterop": true,
+    "sourceMap": true,
+    "inlineSourceMap": false,
+    // This option should cause sourcesContent to be included in the
+    // source map JSON, so we don't have to rely on the (nonexistent)
+    // relative paths in the sources array, but it appears tsc does not
+    // respect this option unless the source maps are inlined into the
+    // source files, which we definitely do not want. Instead, we use the
+    // config/rewriteSourceMaps.ts script to add sourcesContent.
+    "inlineSources": true,
   },
 }

package.json

@@ -33,8 +33,9 @@
   "scripts": {
     "prebuild": "npm run clean",
     "build": "tsc",
-    "postbuild": "npm run invariants && npm run rollup && npm run prepdist && npm run resolve",
+    "postbuild": "npm run invariants && npm run sourcemaps && npm run rollup && npm run prepdist && npm run resolve",
     "invariants": "ts-node-script config/processInvariants.ts",
+    "sourcemaps": "ts-node-script config/rewriteSourceMaps.ts",
     "rollup": "rollup -c ./config/rollup.config.js",
     "prepdist": "node ./config/prepareDist.js",
     "resolve": "ts-node-script config/resolveModuleIds.ts",

src/react/context/ApolloConsumer.tsx

@@ -1,4 +1,4 @@
-import React from 'react';
+import * as React from 'react';
 import { invariant } from 'ts-invariant';
 
 import { ApolloClient } from '../../core';

src/react/context/ApolloContext.ts

@@ -1,5 +1,6 @@
-import React from 'react';
+import * as React from 'react';
 import { ApolloClient } from '../../core';
+import { canUseWeakMap } from '../../utilities';
 
 export interface ApolloContextValue {
   client?: ApolloClient<object>;
@@ -10,27 +11,21 @@ export interface ApolloContextValue {
 // (which can lead to problems like having an Apollo Client instance added
 // in one context, then attempting to retrieve it from another different
 // context), a single Apollo context is created and tracked in global state.
-// Since the created context is React specific, we've decided to attach it to
-// the `React` object for sharing.
+// We use React.createContext as the key instead of just React to avoid
+// ambiguities between default and namespace React imports.
 
-// If Symbol's aren't available, we'll use a fallback string as the context
-// property (we're looking at you, IE11).
-const contextSymbol = typeof Symbol === 'function' && Symbol.for ?
-  Symbol.for('__APOLLO_CONTEXT__') :
-  '__APOLLO_CONTEXT__';
-
-export function resetApolloContext() {
-  Object.defineProperty(React, contextSymbol, {
-    value: React.createContext<ApolloContextValue>({}),
-    enumerable: false,
-    configurable: true,
-    writable: false,
-  });
-}
+const cache = new (canUseWeakMap ? WeakMap : Map)<
+  typeof React.createContext,
+  React.Context<ApolloContextValue>
+>();
 
 export function getApolloContext() {
-  if (!(React as any)[contextSymbol]) {
-    resetApolloContext();
+  let context = cache.get(React.createContext)!;
+  if (!context) {
+    context = React.createContext<ApolloContextValue>({});
+    cache.set(React.createContext, context);
   }
-  return (React as any)[contextSymbol] as React.Context<ApolloContextValue>;
+  return context;
 }
+
+export { getApolloContext as resetApolloContext }

src/react/context/ApolloProvider.tsx

@@ -1,4 +1,4 @@
-import React from 'react';
+import * as React from 'react';
 import { invariant } from 'ts-invariant';
 
 import { ApolloClient } from '../../core';

src/react/hooks/useApolloClient.ts

@@ -1,4 +1,4 @@
-import React from 'react';
+import * as React from 'react';
 import { invariant } from 'ts-invariant';
 
 import { ApolloClient } from '../../core';