Implemented the json stringify and parse filters.

src/renderer/errors.rs

@@ -8,6 +8,7 @@ use std::fmt;
 pub enum RenderError {
     Generic(String),
     TemplateNotFound(String),
+    InvalidJson(String),
 }
 
 #[derive(PartialEq)]
@@ -27,6 +28,11 @@ impl fmt::Display for RenderError {
             RenderError::TemplateNotFound(name) => {
                 write!(f, "No template named {} in context", name)
             }
+            RenderError::InvalidJson(invalid_json) => write!(
+                f,
+                "Attempted to parse the following invalid JSON: {}",
+                invalid_json
+            ),
         }
     }
 }
@@ -38,6 +44,11 @@ impl fmt::Debug for RenderError {
             RenderError::TemplateNotFound(name) => {
                 write!(f, "No template named {} in context", name)
             }
+            RenderError::InvalidJson(invalid_json) => write!(
+                f,
+                "Attempted to parse the following invalid JSON: {}",
+                invalid_json
+            ),
         }
     }
 }