feat(git-master): validate git_env_prefix values

src/config/schema/git-env-prefix.ts

@@ -0,0 +1,28 @@
+import { z } from "zod"
+
+const GIT_ENV_ASSIGNMENT_PATTERN =
+	/^(?:[A-Za-z_][A-Za-z0-9_]*=[A-Za-z0-9_-]*)(?: [A-Za-z_][A-Za-z0-9_]*=[A-Za-z0-9_-]*)*$/
+
+export const GIT_ENV_PREFIX_VALIDATION_MESSAGE =
+	'git_env_prefix must be empty or use shell-safe env assignments like "GIT_MASTER=1"'
+
+export function isValidGitEnvPrefix(value: string): boolean {
+	if (value === "") {
+		return true
+	}
+
+	return GIT_ENV_ASSIGNMENT_PATTERN.test(value)
+}
+
+export function assertValidGitEnvPrefix(value: string): string {
+	if (!isValidGitEnvPrefix(value)) {
+		throw new Error(GIT_ENV_PREFIX_VALIDATION_MESSAGE)
+	}
+
+	return value
+}
+
+export const GitEnvPrefixSchema = z
+	.string()
+	.refine(isValidGitEnvPrefix, { message: GIT_ENV_PREFIX_VALIDATION_MESSAGE })
+	.default("GIT_MASTER=1")