Fix collection doc function

Consider that the snapshot might not exist and be undefined,
in that case return null

Author: kossnocorp

Diff for: package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "typesaurus",
-  "version": "10.0.0-alpha.44",
+  "version": "10.0.0-alpha.45",
   "description": "Type-safe ODM for Firestore",
   "keywords": [
     "Firebase",

Diff for: package.json

@@ -83,7 +83,8 @@ export class Collection {
 
   doc(id, value, options) {
     if (!value && 'id' in id && 'data' in id && typeof id.data === 'function') {
-      return this.doc(id.id, wrapData(id.data()))
+      if (id.exists) return this.doc(id.id, wrapData(id.data()))
+      else return null
     } else {
       assertEnvironment(options?.as)
       return new Doc(this, id, value)
@@ -156,9 +157,7 @@ export class Collection {
           ...ids.map((id) => this.firebaseDoc(id))
         )
         return firebaseSnap.map((firebaseSnap) => {
-          if (!firebaseSnap.exists) {
-            return null
-          }
+          if (!firebaseSnap.exists) return null
           const firestoreData = firebaseSnap.data()
           const data = firestoreData && wrapData(firestoreData)
           return new Doc(this, firebaseSnap.id, data)

Diff for: src/adapter/admin/core.mjs

@@ -102,7 +102,9 @@ export class Collection {
 
   doc(id, value, options) {
     if (!value && 'id' in id && 'data' in id && typeof id.data === 'function') {
-      return this.doc(id.id, wrapData(id.data()))
+      const data = id.data()
+      if (data) return this.doc(id.id, wrapData(data))
+      else return null
     } else {
       assertEnvironment(options?.as)
       return new Doc(this, id, value)

Diff for: src/adapter/web/core.mjs

@@ -138,6 +138,24 @@ describe('doc', () => {
     expect(user.data.birthday.getFullYear()).toBe(1987)
   })
 
+  it('returns null if the snapshot does not exist', async () => {
+    const userId = await db.users.id()
+
+    const path = `users/${userId}`
+    let snapshot
+
+    if (typeof window === 'undefined') {
+      const admin = (await import('firebase-admin')).default
+      snapshot = await admin.firestore().doc(path).get()
+    } else {
+      const { getDoc, doc, getFirestore } = await import('firebase/firestore')
+      snapshot = await getDoc(doc(getFirestore(), path))
+    }
+
+    const doc = db.users.doc(snapshot)
+    expect(doc).toBe(null)
+  })
+
   it('allows to assert environment', async () => {
     const server = () =>
       db.users.doc(

Diff for: src/tests/doc.ts

@@ -878,7 +878,7 @@ export namespace TypesaurusCore {
       Props extends DocProps & { environment: Environment }
     >(
       snapshot: Firebase.Snapshot
-    ): Doc<Def, Props>
+    ): Doc<Def, Props> | null
 
     doc<
       Environment extends RuntimeEnvironment,