initial attempt poc at wasm

.gitignore

@@ -2,6 +2,8 @@
 # will have compiled files and executables
 /target/
 
+wasm/target
+
 # Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
 # More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
 Cargo.lock

wasm/Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+name = "css-inline-wasm"
+version = "0.3.0"
+authors = ["Dmitry Dygalo <[email protected]>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[lib]
+name = "css_inline"
+crate-type = ["cdylib"]
+
+[dependencies.css-inline]
+path = ".."
+version = "= 0.3.3"
+default-features = false
+
+[dependencies]
+url = "2"
+wasm-bindgen = { version = "0.2", features = ["serde-serialize"] }
+serde = { version = "1.0", features = ["derive"] }
+serde_derive = "1"
+serde_json = "1"

wasm/src/lib.rs

@@ -0,0 +1,90 @@
+use css_inline as rust_inline;
+use wasm_bindgen::prelude::*;
+use std::borrow::Cow;
+use std::convert::TryFrom;
+use std::convert::TryInto;
+
+struct InlineErrorWrapper(rust_inline::InlineError);
+
+impl From<InlineErrorWrapper> for JsValue {
+    fn from(error: InlineErrorWrapper) -> Self {
+        JsValue::from_str(error.0.to_string().as_str())
+    }
+}
+
+struct UrlError(url::ParseError);
+
+impl From<UrlError> for JsValue {
+    fn from(error: UrlError) -> Self {
+        wasm_bindgen::throw_str(&error.0.to_string())
+    }
+}
+
+fn parse_url(url: Option<String>) -> Result<Option<url::Url>, JsValue> {
+    Ok(if let Some(url) = url {
+        Some(url::Url::parse(url.as_str()).map_err(UrlError)?)
+    } else {
+        None
+    })
+}
+
+#[macro_use]
+extern crate serde_derive;
+
+#[derive(Deserialize)]
+#[serde(default)]
+pub struct Options {
+    inline_style_tags: bool,
+    remove_style_tags: bool,
+    base_url: Option<String>,
+    load_remote_stylesheets: bool,
+    extra_css: Option<String>,
+}
+
+impl Default for Options {
+    fn default() -> Self {
+        Options {
+            inline_style_tags: true,
+            remove_style_tags: false,
+            base_url: None,
+            load_remote_stylesheets: true,
+            extra_css: None,
+        }
+    }
+}
+
+struct SerdeError(serde_json::Error);
+
+impl From<SerdeError> for JsValue {
+    fn from(error: SerdeError) -> Self {
+        JsValue::from_str(error.0.to_string().as_str())
+    }
+}
+
+impl TryFrom<Options> for rust_inline::InlineOptions<'_> {
+    type Error = JsValue;
+
+    fn try_from(value: Options) -> Result<Self, Self::Error> {
+        Ok(rust_inline::InlineOptions {
+            inline_style_tags: value.inline_style_tags,
+            remove_style_tags: value.remove_style_tags,
+            base_url: parse_url(value.base_url)?,
+            load_remote_stylesheets: value.load_remote_stylesheets,
+            extra_css: value.extra_css.map(Cow::Owned),
+        })
+    }
+}
+
+#[wasm_bindgen]
+pub fn inline(
+    html: &str,
+    options: JsValue,
+) -> Result<String, JsValue> {
+    let options: Options = if !options.is_undefined() {
+        options.into_serde().map_err(SerdeError)?
+    } else {
+        Options::default()
+    };
+    let inliner = rust_inline::CSSInliner::new(options.try_into()?);
+    Ok(inliner.inline(html).map_err(InlineErrorWrapper)?)
+}