worker/
env.rs

1use std::fmt::Display;
2
3use crate::analytics_engine::AnalyticsEngineDataset;
4#[cfg(feature = "d1")]
5use crate::d1::D1Database;
6#[cfg(feature = "queue")]
7use crate::Queue;
8use crate::{durable::ObjectNamespace, Bucket, DynamicDispatcher, Fetcher, Result};
9use crate::{error::Error, hyperdrive::Hyperdrive};
10
11use crate::Ai;
12
13use js_sys::Object;
14use serde::de::DeserializeOwned;
15use wasm_bindgen::{prelude::*, JsCast, JsValue};
16use worker_kv::KvStore;
17
18#[wasm_bindgen]
19extern "C" {
20    /// Env contains any bindings you have associated with the Worker when you uploaded it.
21    #[derive(Clone)]
22    pub type Env;
23}
24
25unsafe impl Send for Env {}
26unsafe impl Sync for Env {}
27
28impl Env {
29    /// Access a binding that does not have a wrapper in workers-rs. Useful for internal-only or
30    /// unstable bindings.
31    pub fn get_binding<T: EnvBinding>(&self, name: &str) -> Result<T> {
32        let binding = js_sys::Reflect::get(self, &JsValue::from(name))
33            .map_err(|_| Error::JsError(format!("Env does not contain binding `{name}`")))?;
34        if binding.is_undefined() {
35            Err(format!("Binding `{name}` is undefined.").into())
36        } else {
37            // Can't just use JsCast::dyn_into here because the type name might not be in scope
38            // resulting in a terribly annoying javascript error which can't be caught
39            T::get(binding)
40        }
41    }
42
43    pub fn ai(&self, binding: &str) -> Result<Ai> {
44        self.get_binding::<Ai>(binding)
45    }
46
47    pub fn analytics_engine(&self, binding: &str) -> Result<AnalyticsEngineDataset> {
48        self.get_binding::<AnalyticsEngineDataset>(binding)
49    }
50
51    /// Access Secret value bindings added to your Worker via the UI or `wrangler`:
52    /// <https://developers.cloudflare.com/workers/cli-wrangler/commands#secret>
53    pub fn secret(&self, binding: &str) -> Result<Secret> {
54        self.get_binding::<Secret>(binding)
55    }
56
57    /// Get an environment variable defined in the [vars] section of your wrangler.toml or a secret
58    /// defined using `wrangler secret` as a plaintext value.
59    ///
60    /// See: <https://developers.cloudflare.com/workers/configuration/environment-variables/>
61    pub fn var(&self, binding: &str) -> Result<Var> {
62        self.get_binding::<Var>(binding)
63    }
64
65    /// Get an environment variable defined in the [vars] section of your wrangler.toml that is
66    /// defined as an object.
67    ///
68    /// See: <https://developers.cloudflare.com/workers/configuration/environment-variables/>
69    pub fn object_var<T: DeserializeOwned>(&self, binding: &str) -> Result<T> {
70        Ok(serde_wasm_bindgen::from_value(
71            self.get_binding::<JsValueWrapper>(binding)?.0,
72        )?)
73    }
74
75    /// Access a Workers KV namespace by the binding name configured in your wrangler.toml file.
76    pub fn kv(&self, binding: &str) -> Result<KvStore> {
77        KvStore::from_this(self, binding).map_err(From::from)
78    }
79
80    /// Access a Durable Object namespace by the binding name configured in your wrangler.toml file.
81    pub fn durable_object(&self, binding: &str) -> Result<ObjectNamespace> {
82        self.get_binding(binding)
83    }
84
85    /// Access a Dynamic Dispatcher for dispatching events to other workers.
86    pub fn dynamic_dispatcher(&self, binding: &str) -> Result<DynamicDispatcher> {
87        self.get_binding(binding)
88    }
89
90    /// Get a [Service Binding](https://developers.cloudflare.com/workers/runtime-apis/service-bindings/)
91    /// for Worker-to-Worker communication.
92    pub fn service(&self, binding: &str) -> Result<Fetcher> {
93        self.get_binding(binding)
94    }
95
96    #[cfg(feature = "queue")]
97    /// Access a Queue by the binding name configured in your wrangler.toml file.
98    pub fn queue(&self, binding: &str) -> Result<Queue> {
99        self.get_binding(binding)
100    }
101
102    /// Access an R2 Bucket by the binding name configured in your wrangler.toml file.
103    pub fn bucket(&self, binding: &str) -> Result<Bucket> {
104        self.get_binding(binding)
105    }
106
107    /// Access a D1 Database by the binding name configured in your wrangler.toml file.
108    #[cfg(feature = "d1")]
109    pub fn d1(&self, binding: &str) -> Result<D1Database> {
110        self.get_binding(binding)
111    }
112
113    /// Access the worker assets by the binding name configured in your wrangler.toml file.
114    pub fn assets(&self, binding: &str) -> Result<Fetcher> {
115        self.get_binding(binding)
116    }
117
118    pub fn hyperdrive(&self, binding: &str) -> Result<Hyperdrive> {
119        self.get_binding(binding)
120    }
121}
122
123pub trait EnvBinding: Sized + JsCast {
124    const TYPE_NAME: &'static str;
125
126    fn get(val: JsValue) -> Result<Self> {
127        let obj = Object::from(val);
128        if obj.constructor().name() == Self::TYPE_NAME {
129            Ok(obj.unchecked_into())
130        } else {
131            Err(format!(
132                "Binding cannot be cast to the type {} from {}",
133                Self::TYPE_NAME,
134                obj.constructor().name()
135            )
136            .into())
137        }
138    }
139}
140
141pub struct StringBinding(JsValue);
142
143impl EnvBinding for StringBinding {
144    const TYPE_NAME: &'static str = "String";
145}
146
147impl JsCast for StringBinding {
148    fn instanceof(val: &JsValue) -> bool {
149        val.is_string()
150    }
151
152    fn unchecked_from_js(val: JsValue) -> Self {
153        StringBinding(val)
154    }
155
156    fn unchecked_from_js_ref(val: &JsValue) -> &Self {
157        unsafe { &*(val as *const JsValue as *const Self) }
158    }
159}
160
161impl AsRef<JsValue> for StringBinding {
162    fn as_ref(&self) -> &wasm_bindgen::JsValue {
163        unsafe { &*(&self.0 as *const JsValue) }
164    }
165}
166
167impl From<JsValue> for StringBinding {
168    fn from(val: JsValue) -> Self {
169        StringBinding(val)
170    }
171}
172
173impl From<StringBinding> for JsValue {
174    fn from(sec: StringBinding) -> Self {
175        sec.0
176    }
177}
178
179impl Display for StringBinding {
180    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::result::Result<(), std::fmt::Error> {
181        write!(f, "{}", self.0.as_string().unwrap_or_default())
182    }
183}
184
185#[repr(transparent)]
186struct JsValueWrapper(JsValue);
187
188impl EnvBinding for JsValueWrapper {
189    const TYPE_NAME: &'static str = "Object";
190}
191
192impl JsCast for JsValueWrapper {
193    fn instanceof(_: &JsValue) -> bool {
194        true
195    }
196
197    fn unchecked_from_js(val: JsValue) -> Self {
198        Self(val)
199    }
200
201    fn unchecked_from_js_ref(val: &JsValue) -> &Self {
202        unsafe { std::mem::transmute(val) }
203    }
204}
205
206impl From<JsValueWrapper> for wasm_bindgen::JsValue {
207    fn from(value: JsValueWrapper) -> Self {
208        value.0
209    }
210}
211
212impl AsRef<JsValue> for JsValueWrapper {
213    fn as_ref(&self) -> &JsValue {
214        &self.0
215    }
216}
217
218/// A string value representing a binding to a secret in a Worker.
219#[doc(inline)]
220pub use StringBinding as Secret;
221/// A string value representing a binding to an environment variable in a Worker.
222pub type Var = StringBinding;
worker/env.rs

worker/
env.rs
