Stop using stdio

README.md

@@ -36,12 +36,11 @@ Here's a simple example of how to use the API:
 
 ```rust
 fn main(context: &mut Context) -> Result<()> {
+    shopify_function_wasm_api::init_panic_handler();
     let input = context.input_get()?;
 
     // Function logic
 
-    context.finalize_output()?;
-
     Ok(())
 }
 ```

api/Cargo.toml

@@ -13,7 +13,7 @@ thiserror = "2.0"
 seq-macro = "0.3.5"
 
 [target.'cfg(not(target_family = "wasm"))'.dependencies]
-shopify_function_provider = { path = "../provider", version = "1.0.1" }
+shopify_function_provider = { path = "../provider", version = "2.0.0" }
 serde_json = "1.0"
 rmp-serde = "1.3"
 
@@ -33,4 +33,3 @@ path = "examples/cart-checkout-validation-wasm-api.rs"
 [[example]]
 name = "cart-checkout-validation-wasi-json"
 path = "examples/cart-checkout-validation-wasi-json.rs"
-

api/examples/cart-checkout-validation-wasm-api.rs

@@ -2,6 +2,7 @@ use shopify_function_wasm_api::{Context, Value};
 use std::error::Error;
 
 fn main() -> Result<(), Box<dyn Error>> {
+    shopify_function_wasm_api::init_panic_handler();
     let mut context = Context::new();
 
     let input = context.input_get()?;
@@ -38,8 +39,6 @@ fn main() -> Result<(), Box<dyn Error>> {
         1,
     )?;
 
-    context.finalize_output()?;
-
     Ok(())
 }
 

api/examples/echo.rs

@@ -5,13 +5,13 @@ use shopify_function_wasm_api::{
 use std::error::Error;
 
 fn main() -> Result<(), Box<dyn Error>> {
+    shopify_function_wasm_api::init_panic_handler();
     let mut context = Context::new();
     let input = context.input_get()?;
 
     let value = Value::deserialize(&input)?;
     let result = echo(value);
     result.serialize(&mut context)?;
-    context.finalize_output()?;
 
     Ok(())
 }

api/examples/log-len.rs

@@ -0,0 +1,14 @@
+use std::error::Error;
+
+use shopify_function_wasm_api::Context;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    shopify_function_wasm_api::init_panic_handler();
+    let mut context = Context::new();
+    let input = context.input_get()?;
+    let len = input.as_number().unwrap() as usize;
+    for _ in 0..len / 100 {
+        context.log(&"a".repeat(100));
+    }
+    Ok(())
+}

api/examples/log-past-capacity.rs

@@ -0,0 +1,11 @@
+use std::error::Error;
+
+use shopify_function_wasm_api::Context;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    shopify_function_wasm_api::init_panic_handler();
+    let mut context = Context::new();
+    context.log(&"a".repeat(1020));
+    context.log(&"b".repeat(10));
+    Ok(())
+}

api/examples/log.rs

@@ -0,0 +1,13 @@
+use std::error::Error;
+
+use shopify_function_wasm_api::Context;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    shopify_function_wasm_api::init_panic_handler();
+    let mut context = Context::new();
+    context.log("Hi!\n");
+    context.log("Hello\n");
+    context.log("Here's a third string\n");
+    context.log("✌️\n");
+    Ok(())
+}

api/examples/panic.rs

@@ -0,0 +1,8 @@
+use std::error::Error;
+
+use shopify_function_wasm_api::init_panic_handler;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    init_panic_handler();
+    panic!("at the disco");
+}

api/src/lib.rs

@@ -9,11 +9,11 @@
 //! use std::error::Error;
 //!
 //! fn main() -> Result<(), Box<dyn Error>> {
+//!     shopify_function_wasm_api::init_panic_handler();
 //!     let mut context = Context::new();
 //!     let input = context.input_get()?;
 //!     let value: i32 = Deserialize::deserialize(&input)?;
 //!     value.serialize(&mut context)?;
-//!     context.finalize_output()?;
 //!     Ok(())
 //! }
 //! ```
@@ -23,18 +23,16 @@
 use shopify_function_wasm_api_core::read::{ErrorCode, NanBox, Val, ValueRef};
 use std::sync::atomic::{AtomicUsize, Ordering};
 
+pub mod log;
 pub mod read;
 pub mod write;
 
 pub use read::Deserialize;
 pub use write::Serialize;
 
 #[cfg(target_family = "wasm")]
-#[link(wasm_import_module = "shopify_function_v1")]
+#[link(wasm_import_module = "shopify_function_v2")]
 extern "C" {
-    // Common API.
-    fn shopify_function_context_new();
-
     // Read API.
     fn shopify_function_input_get() -> Val;
     fn shopify_function_input_get_val_len(scope: Val) -> usize;
@@ -50,7 +48,6 @@ extern "C" {
     // Write API.
     fn shopify_function_output_new_bool(bool: u32) -> usize;
     fn shopify_function_output_new_null() -> usize;
-    fn shopify_function_output_finalize() -> usize;
     fn shopify_function_output_new_i32(int: i32) -> usize;
     fn shopify_function_output_new_f64(float: f64) -> usize;
     fn shopify_function_output_new_utf8_str(ptr: *const u8, len: usize) -> usize;
@@ -62,6 +59,9 @@ extern "C" {
     fn shopify_function_output_new_array(len: usize) -> usize;
     fn shopify_function_output_finish_array() -> usize;
 
+    // Log API.
+    fn shopify_function_log_new_utf8_str(ptr: *const u8, len: usize);
+
     // Other.
     fn shopify_function_intern_utf8_str(ptr: *const u8, len: usize) -> usize;
 }
@@ -119,9 +119,6 @@ mod provider_fallback {
     pub(crate) unsafe fn shopify_function_output_new_null() -> usize {
         shopify_function_provider::write::shopify_function_output_new_null() as usize
     }
-    pub(crate) unsafe fn shopify_function_output_finalize() -> usize {
-        shopify_function_provider::write::shopify_function_output_finalize() as usize
-    }
     pub(crate) unsafe fn shopify_function_output_new_i32(int: i32) -> usize {
         shopify_function_provider::write::shopify_function_output_new_i32(int) as usize
     }
@@ -155,6 +152,20 @@ mod provider_fallback {
         shopify_function_provider::write::shopify_function_output_finish_array() as usize
     }
 
+    // Logging.
+    pub(crate) unsafe fn shopify_function_log_new_utf8_str(ptr: *const u8, len: usize) {
+        let addr = shopify_function_provider::log::shopify_function_log_new_utf8_str(len)
+            as *const [usize; 5];
+        let array = *addr;
+        let source_offset = array[0];
+        let dst_offset1 = array[1];
+        let len1 = array[2];
+        let dst_offset2 = array[3];
+        let len2 = array[4];
+        std::ptr::copy(ptr.add(source_offset) as _, dst_offset1 as _, len1);
+        std::ptr::copy(ptr.add(source_offset).add(len1), dst_offset2 as _, len2);
+    }
+
     // Other.
     pub(crate) unsafe fn shopify_function_intern_utf8_str(ptr: *const u8, len: usize) -> usize {
         let result = shopify_function_provider::shopify_function_intern_utf8_str(len);
@@ -408,7 +419,6 @@ impl Context {
 
         #[cfg(target_family = "wasm")]
         {
-            unsafe { shopify_function_context_new() };
             Self
         }
     }
@@ -419,7 +429,7 @@ impl Context {
     #[cfg(not(target_family = "wasm"))]
     pub fn new_with_input(input: serde_json::Value) -> Self {
         let bytes = rmp_serde::to_vec(&input).unwrap();
-        shopify_function_provider::shopify_function_context_new_from_msgpack_bytes(bytes);
+        shopify_function_provider::initialize_from_msgpack_bytes(bytes);
         Self
     }
 
@@ -448,6 +458,15 @@ impl Default for Context {
     }
 }
 
+/// Configures panics to write to the logging API.
+pub fn init_panic_handler() {
+    #[cfg(target_family = "wasm")]
+    std::panic::set_hook(Box::new(|info| {
+        let message = format!("{info}");
+        log::log_utf8_str(&message);
+    }));
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

api/src/log.rs

@@ -0,0 +1,14 @@
+//! The log API for the Shopify Function Wasm API.
+
+use crate::Context;
+
+pub(super) fn log_utf8_str(message: &str) {
+    unsafe { crate::shopify_function_log_new_utf8_str(message.as_ptr(), message.len()) };
+}
+
+impl Context {
+    /// Log `message`.
+    pub fn log(&mut self, message: &str) {
+        log_utf8_str(message)
+    }
+}

api/src/shopify_function.h

@@ -14,15 +14,7 @@ typedef size_t InternedStringId;
 #define WRITE_RESULT_ERROR 1
 
 // Import module declaration
-#define SHOPIFY_FUNCTION_IMPORT_MODULE "shopify_function_v1"
-
-// Common API
-/**
- * Creates a new context for the Shopify Function execution
- */
-__attribute__((import_module(SHOPIFY_FUNCTION_IMPORT_MODULE)))
-__attribute__((import_name("shopify_function_context_new")))
-extern void shopify_function_context_new(void);
+#define SHOPIFY_FUNCTION_IMPORT_MODULE "shopify_function_v2"
 
 // Read API
 /**
@@ -111,14 +103,6 @@ __attribute__((import_module(SHOPIFY_FUNCTION_IMPORT_MODULE)))
 __attribute__((import_name("shopify_function_output_new_null")))
 extern WriteResult shopify_function_output_new_null();
 
-/**
- * Finalizes the output and returns the result
- * @return WriteResult indicating success or failure
- */
-__attribute__((import_module(SHOPIFY_FUNCTION_IMPORT_MODULE)))
-__attribute__((import_name("shopify_function_output_finalize")))
-extern WriteResult shopify_function_output_finalize();
-
 /**
  * Creates a new 32-bit integer output value
  * @param value The integer value
@@ -201,4 +185,13 @@ __attribute__((import_module(SHOPIFY_FUNCTION_IMPORT_MODULE)))
 __attribute__((import_name("shopify_function_intern_utf8_str")))
 extern InternedStringId shopify_function_intern_utf8_str(const uint8_t* ptr, size_t len);
 
+/**
+ * Logs a new UTF-8 string output value
+ * @param ptr The string data
+ * @param len The length of the string
+ */
+__attribute__((import_module(SHOPIFY_FUNCTION_IMPORT_MODULE)))
+__attribute__((import_name("shopify_function_log_new_utf8_str")))
+extern void shopify_function_log_new_utf8_str(const uint8_t* ptr, size_t len);
+
 #endif // SHOPIFY_FUNCTION_H