Skip split require calls by identity and climb parentheses in early-read checks

packages/compiler/src/frontend/program.ts

@@ -1563,6 +1563,14 @@ function splitRequireOfStatement7(
   return null;
 }
 
+/** The top-level statement of a split require binding's assignment, from
+ * its require call (`m = require("./x")` or `m = (require("./x"))`). */
+function splitRequireStatementOf7(call: ts.CallExpression): ts.Node | undefined {
+  let node: ts.Node = call;
+  while (node.parent !== undefined && ts.isParenthesizedExpression(node.parent)) node = node.parent;
+  return node.parent?.parent;
+}
+
 /** The require call of a split require binding's declaration, or null. */
 function splitRequireCallOf7(
   program: ts.Program,
@@ -1877,7 +1885,7 @@ function requireEarlyReference7(
   const sf = ts.getSourceFileOfNode(decl);
   // A split require binding is bound at its assignment statement.
   const splitCall = splitRequireCallOf7(program, decl);
-  const stmt = splitCall !== null ? splitCall.parent?.parent : decl.parent?.parent;
+  const stmt = splitCall !== null ? splitRequireStatementOf7(splitCall) : decl.parent?.parent;
   if (
     stmt !== undefined &&
     (ts.isVariableStatement(stmt) || splitCall !== null) &&
@@ -6184,15 +6192,12 @@ function preflight7(load: LoadResult): {
       // counts, and targets outside the compiled graph add nothing here:
       // their use sites keep their existing lowering fences.
       if (jsRequireFile && !isNodeEsmFile7(sf, program)) {
+        // A split require binding's assignment is a statement-level require
+        // edge (requiresOf7 above), parenthesized or not.
+        const splitCalls = new Set(splitRequireBindings7(program, sf).values());
         for (const call of inlineRequiresOf7(sf)) {
           if (requireCallBindingKind7(program, call) !== "ambient") continue;
-          // A split require binding's assignment is a statement-level
-          // require edge (requiresOf7 above).
-          if (
-            call.parent?.parent !== undefined &&
-            splitRequireOfStatement7(program, call.parent.parent as ts.Statement) !== null
-          )
-            continue;
+          if (splitCalls.has(call)) continue;
           const spec = requireSpecOf7(call)!;
           if (load.externalTypes.has(spec) || canonicalBuiltinModule(spec) !== null) continue;
           const lazy = inDeferredPosition7(call);

packages/compiler/test/ts7/baselines/order-parity/tests/diagnostics/split-cjs-require-early/main.js.json

@@ -12,6 +12,16 @@
     "end": 415
    },
    "milestone": "later"
+  },
+  {
+   "code": "SC1013",
+   "message": "require() binding 'wrapped' assigned below code that can reach it (Node reads undefined before the assignment runs, which is not modeled — move the assignment above the code that can run first) is not supported yet",
+   "loc": {
+    "file": "<repo>/tests/diagnostics/split-cjs-require-early/main.js",
+    "start": 530,
+    "end": 549
+   },
+   "milestone": "later"
   }
  ]
 }

tests/corpus/split-cjs-require-cycle/main.cjs

@@ -1,7 +1,8 @@
 // Split require bindings (`var m; m = require("./x.cjs")`) that close a
 // CommonJS cycle: each module publishes its exports before its require, and
 // reads the other module's binding only in functions that run after both
-// modules finish, the cycle shape the const form compiles too.
+// modules finish, the cycle shape the const form compiles too. One
+// assignment parenthesizes its require.
 console.log("main: start");
 var even, odd;
 even = require("./even.cjs");

tests/corpus/split-cjs-require-cycle/odd.cjs

@@ -8,5 +8,5 @@ exports.isOdd = function (n) {
 exports.calls = function () {
   return calls;
 };
-even = require("./even.cjs");
+even = (require("./even.cjs"));
 console.log("odd: loaded");

tests/diagnostics/split-cjs-require-early/main.js

@@ -9,6 +9,11 @@ let lib;
 console.log('boot', helper());
 lib = require('./lib.js');
 
+// The same with the require parenthesized.
+let wrapped;
+console.log('peek', wrapped === undefined);
+wrapped = (require('./lib.js'));
+
 function helper() {
   return lib === undefined ? 'not loaded' : lib.greet('late');
 }

tests/harness/__snapshots__/split-cjs-require-early/main.js.txt

@@ -3,4 +3,11 @@ split-cjs-require-early/main.js:10:7 - error SC1013: require() binding 'lib' ass
    9 | console.log('boot', helper());
   10 | lib = require('./lib.js');
      |       ^~~~~~~~~~~~~~~~~~~
-  11 | 
+  11 | 
+
+split-cjs-require-early/main.js:15:12 - error SC1013: require() binding 'wrapped' assigned below code that can reach it (Node reads undefined before the assignment runs, which is not modeled — move the assignment above the code that can run first) is not supported yet
+
+  14 | console.log('peek', wrapped === undefined);
+  15 | wrapped = (require('./lib.js'));
+     |            ^~~~~~~~~~~~~~~~~~~
+  16 |