From 1b964dce938573ef7063d658fac0ca60a37d8900 Mon Sep 17 00:00:00 2001
From: Billy Le <hi@billyle.dev>
Date: Thu, 8 Aug 2024 23:05:10 +0800
Subject: [PATCH] fix/actions-default-values: set default values from zod if
 FormData key is not present

---
 .changeset/nervous-garlics-beam.md            |  5 ++
 .../src/actions/runtime/virtual/server.ts     | 15 ++++++
 .../units/actions/form-data-to-object.test.js | 48 +++++++++++++++++++
 3 files changed, 68 insertions(+)
 create mode 100644 .changeset/nervous-garlics-beam.md

diff --git a/.changeset/nervous-garlics-beam.md b/.changeset/nervous-garlics-beam.md
new file mode 100644
index 0000000000000..6ba4b66ff95d3
--- /dev/null
+++ b/.changeset/nervous-garlics-beam.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Set action input default values from zod if FormData key is not present
diff --git a/packages/astro/src/actions/runtime/virtual/server.ts b/packages/astro/src/actions/runtime/virtual/server.ts
index a711f10326fc1..2d3f2409abfc6 100644
--- a/packages/astro/src/actions/runtime/virtual/server.ts
+++ b/packages/astro/src/actions/runtime/virtual/server.ts
@@ -137,6 +137,21 @@ export function formDataToObject<T extends z.AnyZodObject>(
 		while (validator instanceof z.ZodOptional || validator instanceof z.ZodNullable) {
 			validator = validator._def.innerType;
 		}
+
+		// use zod default value when key is undefined
+   		// else continue to get correct zod class
+		if(validator instanceof z.ZodDefault) {
+			if(!formData.has(key)) {
+				obj[key] = validator._def.defaultValue();
+				continue;
+			}
+
+			while (validator instanceof z.ZodOptional || validator instanceof z.ZodNullable) {
+				validator = validator._def.innerType;
+			}
+		}
+		
+
 		if (validator instanceof z.ZodBoolean) {
 			obj[key] = formData.has(key);
 		} else if (validator instanceof z.ZodArray) {
diff --git a/packages/astro/test/units/actions/form-data-to-object.test.js b/packages/astro/test/units/actions/form-data-to-object.test.js
index 6cce8f3d7df44..2728c31d0f38e 100644
--- a/packages/astro/test/units/actions/form-data-to-object.test.js
+++ b/packages/astro/test/units/actions/form-data-to-object.test.js
@@ -91,6 +91,37 @@ describe('formDataToObject', () => {
 		assert.equal(res.age, null);
 	});
 
+	it('should handle zod default values', () => {
+		const formData = new FormData();
+		
+		const input = z.object({
+			name: z.string().default("test"),
+			email: z.string().default('test@test.test'),
+			favoriteNumbers: z.array(z.number()).default([1,2])
+		});
+
+		const res = formDataToObject(formData, input);
+		assert.equal(res.name, 'test');
+		assert.equal(res.email, 'test@test.test');
+		assert.deepEqual(res.favoriteNumbers, [1, 2]);
+	})
+
+	it('should handle zod chaining of optional, default, and nullish values', () => {
+		const formData = new FormData();
+		formData.set('email', 'test@test.test')
+		
+		const input = z.object({
+			name: z.string().default("test").optional(),
+			email: z.string().optional().nullish(),
+			favoriteNumbers: z.array(z.number()).default([1,2]).nullish().optional()
+		});
+
+		const res = formDataToObject(formData, input);
+		assert.equal(res.name, 'test');
+		assert.equal(res.email, 'test@test.test');
+		assert.deepEqual(res.favoriteNumbers, [1, 2])
+	})
+
 	it('should handle File objects', () => {
 		const formData = new FormData();
 		formData.set('file', new File([''], 'test.txt'));
@@ -135,4 +166,21 @@ describe('formDataToObject', () => {
 		assert.ok(Array.isArray(res.age), 'age is not an array');
 		assert.deepEqual(res.age.sort(), [25, 30, 35]);
 	});
+
+	it('should handle an array of File objects', () => {
+		const formData = new FormData();
+		const file1 = new File([''], 'test1.txt');
+		const file2 = new File([''], 'test2.txt')
+		formData.append('files', file1);
+		formData.append('files', file2);
+
+		const input = z.object({
+			files: z.array(z.instanceof(File))
+		});
+
+		const res = formDataToObject(formData, input);
+
+		assert.equal(res.files instanceof Array, true);
+		assert.deepEqual(res.files, [file1, file2])
+	});
 });