see #11, see #12

wip

src/lib.rs

@@ -10,12 +10,14 @@ pub mod fetch;
 
 pub mod moduleloaders;
 pub mod modules;
+pub mod preprocessors;
 
 pub fn new_greco_rt_builder() -> EsRuntimeBuilder {
     let mut rt_builder = EsRuntimeBuilder::new();
 
     rt_builder = modules::init(rt_builder);
     rt_builder = features::init(rt_builder);
+    rt_builder = preprocessors::init(rt_builder);
 
     rt_builder
 }

src/preprocessors/ifdef.rs

@@ -0,0 +1,41 @@
+use quickjs_runtime::esruntime::ScriptPreProcessor;
+use quickjs_runtime::esscript::EsScript;
+
+pub struct IfDefPreProcessor {
+    defs: Vec<&'static str>,
+    extensions: Vec<&'static str>,
+}
+
+impl IfDefPreProcessor {
+    pub fn new() -> Self {
+        Self {
+            defs: vec![],
+            extensions: vec![],
+        }
+    }
+    /// add a def
+    pub fn def(mut self, var: &'static str) -> Self {
+        self.defs.push(var);
+        self
+    }
+    /// add a supported extension e.g. js/mjs/ts/mts/es/mes
+    pub fn extension(mut self, ext: &'static str) -> Self {
+        self.extensions.push(ext);
+        self
+    }
+    /// add default extensions : js/mjs/ts/mts/es/mes
+    pub fn default_extensions(self) -> Self {
+        self.extension("es")
+            .extension("mes")
+            .extension("js")
+            .extension("mjs")
+            .extension("ts")
+            .extension("mts")
+    }
+}
+
+impl ScriptPreProcessor for IfDefPreProcessor {
+    fn process(&self, script: EsScript) -> EsScript {
+        script
+    }
+}

src/preprocessors/macros.rs

@@ -0,0 +1,16 @@
+use quickjs_runtime::esruntime::ScriptPreProcessor;
+use quickjs_runtime::esscript::EsScript;
+
+pub struct MacrosPreProcessor {}
+
+impl MacrosPreProcessor {
+    pub fn new() -> Self {
+        Self {}
+    }
+}
+
+impl ScriptPreProcessor for MacrosPreProcessor {
+    fn process(&self, script: EsScript) -> EsScript {
+        script
+    }
+}

src/preprocessors/mod.rs

@@ -0,0 +1,21 @@
+//! IfDefPreProcessor
+//!
+//! this is a script preprocessor which can be used to conditionally load/unload pieces of script before compilation or evaluation
+//!
+//! # Example
+//! ```javascript
+//!
+//! ```
+
+use crate::preprocessors::ifdef::IfDefPreProcessor;
+use crate::preprocessors::macros::MacrosPreProcessor;
+use quickjs_runtime::esruntimebuilder::EsRuntimeBuilder;
+
+pub mod ifdef;
+pub mod macros;
+
+pub(crate) fn init(builder: EsRuntimeBuilder) -> EsRuntimeBuilder {
+    builder
+        .script_pre_processor(MacrosPreProcessor::new())
+        .script_pre_processor(IfDefPreProcessor::new().default_extensions())
+}