Revert "implement Context-local functions and ergonomic wrappers marking functions as safe (#666)"

This reverts commit 34435db.

Author: Keats

src/builtins/functions.rs

@@ -8,26 +8,6 @@ use serde_json::value::{from_value, to_value, Value};
 
 use crate::errors::{Error, Result};
 
-/// The context-local function type definition
-pub trait FunctionRelaxed {
-    /// The context-local function type definition
-    fn call(&self, args: &HashMap<String, Value>) -> Result<Value>;
-
-    /// Whether the current function's output should be treated as safe, defaults to `false`
-    fn is_safe(&self) -> bool {
-        false
-    }
-}
-
-impl<F> FunctionRelaxed for F
-where
-    F: Fn(&HashMap<String, Value>) -> Result<Value>,
-{
-    fn call(&self, args: &HashMap<String, Value>) -> Result<Value> {
-        self(args)
-    }
-}
-
 /// The global function type definition
 pub trait Function: Sync + Send {
     /// The global function type definition
@@ -48,43 +28,6 @@ where
     }
 }
 
-macro_rules! safe_function {
-    ($function_trait:ident, $function_wrapper:ident) => {
-        /// Wrapper to make `is_safe` return `true` instead of `false` for a trait implementation.
-        pub struct $function_wrapper<F>
-        where
-            F: $function_trait,
-        {
-            inner: F,
-        }
-
-        impl<F> $function_trait for $function_wrapper<F>
-        where
-            F: $function_trait,
-        {
-            fn call(&self, args: &HashMap<String, Value>) -> Result<Value> {
-                self.inner.call(args)
-            }
-
-            fn is_safe(&self) -> bool {
-                true
-            }
-        }
-
-        impl<F> From<F> for $function_wrapper<F>
-        where
-            F: $function_trait,
-        {
-            fn from(func: F) -> Self {
-                $function_wrapper { inner: func }
-            }
-        }
-    };
-}
-
-safe_function!(FunctionRelaxed, FunctionRelaxedSafe);
-safe_function!(Function, FunctionSafe);
-
 pub fn range(args: &HashMap<String, Value>) -> Result<Value> {
     let start = match args.get("start") {
         Some(val) => match from_value::<usize>(val.clone()) {

src/context.rs

@@ -5,39 +5,20 @@ use serde::ser::Serialize;
 use serde_json::value::{to_value, Map, Value};
 
 use crate::errors::{Error, Result as TeraResult};
-use crate::FunctionRelaxed;
-use std::sync::Arc;
 
 /// The struct that holds the context of a template rendering.
 ///
 /// Light wrapper around a `BTreeMap` for easier insertions of Serializable
 /// values
-#[derive(Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct Context {
     data: BTreeMap<String, Value>,
-    /// Ignored by PartialEq!
-    functions: BTreeMap<String, Arc<dyn FunctionRelaxed>>,
-}
-
-impl std::fmt::Debug for Context {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.debug_struct("Context")
-            .field("data", &self.data)
-            .field("functions", &self.functions.keys())
-            .finish()
-    }
-}
-
-impl PartialEq for Context {
-    fn eq(&self, other: &Self) -> bool {
-        self.data.eq(&other.data)
-    }
 }
 
 impl Context {
     /// Initializes an empty context
     pub fn new() -> Self {
-        Context { data: BTreeMap::new(), functions: Default::default() }
+        Context { data: BTreeMap::new() }
     }
 
     /// Converts the `val` parameter to `Value` and insert it into the context.
@@ -82,15 +63,6 @@ impl Context {
         Ok(())
     }
 
-    /// Registers Context-local function
-    pub fn register_function<T: FunctionRelaxed + 'static, S: Into<String>>(
-        &mut self,
-        key: S,
-        val: T,
-    ) {
-        self.functions.insert(key.into(), Arc::new(val));
-    }
-
     /// Appends the data of the `source` parameter to `self`, overwriting existing keys.
     /// The source context will be dropped.
     ///
@@ -125,7 +97,7 @@ impl Context {
                 for (key, value) in m {
                     data.insert(key, value);
                 }
-                Ok(Context { data, functions: Default::default() })
+                Ok(Context { data })
             }
             _ => Err(Error::msg(
                 "Creating a Context from a Value/Serialize requires it being a JSON object",
@@ -155,12 +127,6 @@ impl Context {
     pub fn contains_key(&self, index: &str) -> bool {
         self.data.contains_key(index)
     }
-
-    /// Looks up Context-local registered function
-    #[inline]
-    pub fn get_function(&self, fn_name: &str) -> Option<&Arc<dyn FunctionRelaxed>> {
-        self.functions.get(fn_name)
-    }
 }
 
 impl Default for Context {

src/lib.rs

@@ -7,7 +7,6 @@
 //! See the [site](https://tera.netlify.com) for features and to get started.
 
 #![deny(missing_docs)]
-#![deny(warnings)]
 
 #[macro_use]
 mod macros;
@@ -24,9 +23,7 @@ mod utils;
 // Library exports.
 
 pub use crate::builtins::filters::Filter;
-pub use crate::builtins::functions::{
-    Function, FunctionRelaxed, FunctionRelaxedSafe, FunctionSafe,
-};
+pub use crate::builtins::functions::Function;
 pub use crate::builtins::testers::Test;
 pub use crate::context::Context;
 pub use crate::errors::{Error, ErrorKind, Result};

src/renderer/call_stack.rs

@@ -8,8 +8,7 @@ use crate::errors::{Error, Result};
 use crate::renderer::for_loop::{ForLoop, ForLoopState};
 use crate::renderer::stack_frame::{FrameContext, FrameType, StackFrame, Val};
 use crate::template::Template;
-use crate::{Context, FunctionRelaxed};
-use std::sync::Arc;
+use crate::Context;
 
 /// Contains the user data and allows no mutation
 #[derive(Debug)]
@@ -132,10 +131,6 @@ impl<'a> CallStack<'a> {
         None
     }
 
-    pub fn lookup_function(&self, fn_name: &str) -> Option<&Arc<dyn FunctionRelaxed>> {
-        self.context.inner.get_function(fn_name)
-    }
-
     /// Add an assignment value (via {% set ... %} and {% set_global ... %} )
     pub fn add_assignment(&mut self, key: &'a str, global: bool, value: Val<'a>) {
         if global {

src/renderer/processor.rs

@@ -491,6 +491,9 @@ impl<'a> Processor<'a> {
         function_call: &'a FunctionCall,
         needs_escape: &mut bool,
     ) -> Result<Val<'a>> {
+        let tera_fn = self.tera.get_function(&function_call.name)?;
+        *needs_escape = !tera_fn.is_safe();
+
         let err_wrap = |e| Error::call_function(&function_call.name, e);
 
         let mut args = HashMap::new();
@@ -501,15 +504,7 @@ impl<'a> Processor<'a> {
             );
         }
 
-        if let Some(tera_fn) = self.call_stack.lookup_function(&function_call.name) {
-            *needs_escape = !tera_fn.is_safe();
-            Ok(Cow::Owned(tera_fn.call(&args).map_err(err_wrap)?))
-        } else {
-            let tera_fn = self.tera.get_function(&function_call.name)?;
-            *needs_escape = !tera_fn.is_safe();
-
-            Ok(Cow::Owned(tera_fn.call(&args).map_err(err_wrap)?))
-        }
+        Ok(Cow::Owned(tera_fn.call(&args).map_err(err_wrap)?))
     }
 
     fn eval_macro_call(&mut self, macro_call: &'a MacroCall, write: &mut impl Write) -> Result<()> {