fix: Parse boolean env var with zod

See the note on boolean coercion [here](https://v3.zod.dev/?id=coercion-for-primitives)

Author: spalladino

yarn-project/end-to-end/src/spartan/utils.ts

@@ -2,6 +2,7 @@ import { createLogger, sleep } from '@aztec/aztec.js';
 import type { RollupCheatCodes } from '@aztec/aztec/testing';
 import type { Logger } from '@aztec/foundation/log';
 import { makeBackoff, retry } from '@aztec/foundation/retry';
+import { schemas } from '@aztec/foundation/schemas';
 import { type AztecNodeAdminConfig, createAztecNodeAdminClient } from '@aztec/stdlib/interfaces/client';
 
 import { ChildProcess, exec, execSync, spawn } from 'child_process';
@@ -15,13 +16,15 @@ const logger = createLogger('e2e:k8s-utils');
 
 const testConfigSchema = z.object({
   NAMESPACE: z.string().default('scenario'),
-  REAL_VERIFIER: z.coerce.boolean().default(true),
+  REAL_VERIFIER: schemas.Boolean.optional().default(true),
 });
 
 export type TestConfig = z.infer<typeof testConfigSchema>;
 
 export function setupEnvironment(env: unknown): TestConfig {
-  return testConfigSchema.parse(env);
+  const config = testConfigSchema.parse(env);
+  logger.warn(`Loaded env config`, config);
+  return config;
 }
 
 /**

yarn-project/foundation/src/schemas/schemas.test.ts

@@ -0,0 +1,48 @@
+import { schemas } from './schemas.js';
+
+describe('schemas', () => {
+  describe('Boolean', () => {
+    it('accepts a boolean value', () => {
+      expect(schemas.Boolean.parse(true)).toEqual(true);
+      expect(schemas.Boolean.parse(false)).toEqual(false);
+    });
+
+    it('accepts a numeric value', () => {
+      expect(schemas.Boolean.parse(1)).toEqual(true);
+      expect(schemas.Boolean.parse(0)).toEqual(false);
+    });
+
+    it('rejects a non binary numeric value', () => {
+      expect(schemas.Boolean.safeParse(2).success).toEqual(false);
+    });
+
+    it('accepts string values', () => {
+      expect(schemas.Boolean.parse('true')).toEqual(true);
+      expect(schemas.Boolean.parse('false')).toEqual(false);
+      expect(schemas.Boolean.parse('TRUE')).toEqual(true);
+      expect(schemas.Boolean.parse('FALSE')).toEqual(false);
+      expect(schemas.Boolean.parse('True')).toEqual(true);
+      expect(schemas.Boolean.parse('False')).toEqual(false);
+      expect(schemas.Boolean.parse(' true ')).toEqual(true);
+      expect(schemas.Boolean.parse(' false ')).toEqual(false);
+    });
+
+    it('accepts numeric values as string', () => {
+      expect(schemas.Boolean.parse('1')).toEqual(true);
+      expect(schemas.Boolean.parse('0')).toEqual(false);
+    });
+
+    it('rejects other string values', () => {
+      expect(schemas.Boolean.safeParse('falso').success).toEqual(false);
+    });
+
+    it('rejects empty strings', () => {
+      expect(schemas.Boolean.safeParse('').success).toEqual(false);
+    });
+
+    it('handles defaults', () => {
+      expect(schemas.Boolean.optional().default(true).parse(undefined)).toEqual(true);
+      expect(schemas.Boolean.optional().default(false).parse(undefined)).toEqual(false);
+    });
+  });
+});

yarn-project/foundation/src/schemas/schemas.ts

@@ -21,6 +21,20 @@ export const schemas = {
   /** Point. Serialized as a hex string. */
   Point: Point.schema,
 
+  /** Coerces truthy-like string values to boolean. */
+  Boolean: z.union([
+    z.boolean(),
+    z
+      .number()
+      .refine(arg => arg === 0 || arg === 1, { message: `Numeric value for a boolean variable must be 0 or 1` })
+      .transform(arg => arg === 1),
+    z
+      .string()
+      .transform(arg => arg.trim().toLowerCase())
+      .refine(arg => ['true', 'false', '1', '0'].includes(arg))
+      .transform(arg => arg === '1' || arg === 'true'),
+  ]),
+
   /** Coerces any input to bigint. */
   BigInt: z.union([z.bigint(), z.number(), z.string()]).pipe(z.coerce.bigint()),