Forbidden variable names validation

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Pipeline.ts

@@ -86,6 +86,7 @@ import {
   validateMemoizedEffectDependencies,
   validateNoCapitalizedCalls,
   validateNoRefAccessInRender,
+  validateNoForbiddenVariableNames,
   validateNoSetStateInRender,
   validatePreservedManualMemoization,
   validateUseMemo,
@@ -247,6 +248,10 @@ function runWithEnvironment(
     }
   }
 
+  if (env.config.validateNoForbiddenVariableNames) {
+    validateNoForbiddenVariableNames(hir);
+  }
+
   if (!env.config.enableNewMutationAliasingModel) {
     validateLocalsNotReassignedAfterRender(hir);
   }

compiler/packages/babel-plugin-react-compiler/src/HIR/Environment.ts

@@ -330,6 +330,11 @@ export const EnvironmentConfigSchema = z.object({
    */
   validateNoSetStateInEffects: z.boolean().default(false),
 
+  /*
+   * Validates there are no forbidden variable names in the component.
+   */
+  validateNoForbiddenVariableNames:z.boolean().default(false),
+
   /**
    * Validates that effects are not used to calculate derived data which could instead be computed
    * during render.

compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoForbiddenVariableNames.ts

@@ -0,0 +1,31 @@
+import {
+  GeneratedSource,
+  HIRFunction,
+} from '../HIR';
+
+import {CompilerError, ErrorSeverity} from '..';
+export function validateNoForbiddenVariableNames(fn: HIRFunction) {
+  const errors = new CompilerError();
+
+  for (const block of fn.body.blocks.values()) {
+    for (const instr of block.instructions) {
+      const {loc} = instr;
+
+      console.log(instr)
+      if (loc !== GeneratedSource && loc.identifierName === 'forbidden') {
+        errors.push({
+          reason:
+            'Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)',
+          description: null,
+          severity: ErrorSeverity.InvalidReact,
+          loc,
+          suggestions: null,
+        });
+      }
+    }}
+
+
+  if (errors.hasErrors()) {
+    throw errors;
+  }
+}

compiler/packages/babel-plugin-react-compiler/src/Validation/index.ts

@@ -11,5 +11,6 @@ export {validateMemoizedEffectDependencies} from './ValidateMemoizedEffectDepend
 export {validateNoCapitalizedCalls} from './ValidateNoCapitalizedCalls';
 export {validateNoRefAccessInRender} from './ValidateNoRefAccessInRender';
 export {validateNoSetStateInRender} from './ValidateNoSetStateInRender';
+export {validateNoForbiddenVariableNames} from './ValidateNoForbiddenVariableNames';
 export {validatePreservedManualMemoization} from './ValidatePreservedManualMemoization';
 export {validateUseMemo} from './ValidateUseMemo';