Merge pull request #322 from overlisted/rsx-errors

Improve `rsx!` errors

Cargo.toml

@@ -51,7 +51,6 @@ liveview = ["dioxus-liveview"]
 members = [
     "packages/core",
     "packages/core-macro",
-    "packages/rsx",
     "packages/html",
     "packages/hooks",
     "packages/web",

packages/core-macro/src/rsx/component.rs

@@ -199,8 +199,7 @@ impl Parse for ComponentField {
         }
 
         if input.peek(LitStr) && input.peek2(LitStr) {
-            let item = input.parse::<LitStr>().unwrap();
-            proc_macro_error::emit_error!(item, "This attribute is missing a trailing comma")
+            missing_trailing_comma!(input.span());
         }
 
         let content = ContentField::ManExpr(input.parse()?);

packages/core-macro/src/rsx/element.rs

@@ -63,12 +63,8 @@ impl Parse for Element {
                     break;
                 }
 
-                // todo: add a message saying you need to include commas between fields
                 if content.parse::<Token![,]>().is_err() {
-                    proc_macro_error::emit_error!(
-                        ident,
-                        "This attribute is missing a trailing comma"
-                    )
+                    missing_trailing_comma!(ident);
                 }
                 continue;
             }
@@ -126,10 +122,7 @@ impl Parse for Element {
 
                 // todo: add a message saying you need to include commas between fields
                 if content.parse::<Token![,]>().is_err() {
-                    proc_macro_error::emit_error!(
-                        ident,
-                        "This attribute is missing a trailing comma"
-                    )
+                    missing_trailing_comma!(ident);
                 }
                 continue;
             }
@@ -139,33 +132,11 @@ impl Parse for Element {
 
         while !content.is_empty() {
             if (content.peek(LitStr) && content.peek2(Token![:])) && !content.peek3(Token![:]) {
-                let ident = content.parse::<LitStr>().unwrap();
-                let name = ident.value();
-                proc_macro_error::emit_error!(
-                    ident, "This attribute `{}` is in the wrong place.", name;
-                    help =
-"All attribute fields must be placed above children elements.
-
-                div {
-                   attr: \"...\",  <---- attribute is above children
-                   div { }       <---- children are below attributes
-                }";
-                )
+                attr_after_element!(content.span());
             }
 
             if (content.peek(Ident) && content.peek2(Token![:])) && !content.peek3(Token![:]) {
-                let ident = content.parse::<Ident>().unwrap();
-                let name = ident.to_string();
-                proc_macro_error::emit_error!(
-                    ident, "This attribute `{}` is in the wrong place.", name;
-                    help =
-"All attribute fields must be placed above children elements.
-
-                div {
-                   attr: \"...\",  <---- attribute is above children
-                   div { }       <---- children are below attributes
-                }";
-                )
+                attr_after_element!(content.span());
             }
 
             children.push(content.parse::<BodyNode>()?);

packages/core-macro/src/rsx/errors.rs

@@ -0,0 +1,15 @@
+macro_rules! missing_trailing_comma {
+    ($span:expr) => {
+        proc_macro_error::emit_error!($span, "missing trailing comma")
+    };
+}
+
+macro_rules! attr_after_element {
+    ($span:expr) => {
+        proc_macro_error::emit_error!(
+            $span,
+            "expected element";
+            help = "move the attribute above all the children and text elements"
+        )
+    };
+}

packages/core-macro/src/rsx/mod.rs

@@ -11,6 +11,9 @@
 //!
 //! Any errors in using rsx! will likely occur when people start using it, so the first errors must be really helpful.
 
+#[macro_use]
+mod errors;
+
 mod component;
 mod element;
 mod node;

packages/rsx/Cargo.toml

@@ -1,12 +0,0 @@
-[package]
-name = "dioxus-rsx"
-version = "0.1.0"
-edition = "2018"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[dependencies]
-proc-macro-error = "1"
-proc-macro2 = { version = "1.0.6" }
-quote = "1.0"
-syn = { version = "1.0.11", features = ["full", "extra-traits"] }

packages/rsx/src/component.rs

@@ -1,234 +0,0 @@
-//! Parse components into the VComponent VNode
-//! ==========================================
-//!
-//! This parsing path emerges from [`AmbiguousElement`] which supports validation of the vcomponent format.
-//! We can be reasonably sure that whatever enters this parsing path is in the right format.
-//! This feature must support
-//! - [x] Namespaced components
-//! - [x] Fields
-//! - [x] Componentbuilder synax
-//! - [x] Optional commas
-//! - [ ] Children
-//! - [ ] Keys
-//! - [ ] Properties spreading with with `..` syntax
-
-use super::*;
-
-use proc_macro2::TokenStream as TokenStream2;
-use quote::{quote, ToTokens, TokenStreamExt};
-use syn::{
-    ext::IdentExt,
-    parse::{Parse, ParseBuffer, ParseStream},
-    token, Expr, Ident, LitStr, Result, Token,
-};
-
-pub struct Component {
-    pub name: syn::Path,
-    pub body: Vec<ComponentField>,
-    pub children: Vec<BodyNode>,
-    pub manual_props: Option<Expr>,
-}
-
-impl Parse for Component {
-    fn parse(stream: ParseStream) -> Result<Self> {
-        let name = syn::Path::parse_mod_style(stream)?;
-
-        let content: ParseBuffer;
-
-        // if we see a `{` then we have a block
-        // else parse as a function-like call
-        if stream.peek(token::Brace) {
-            syn::braced!(content in stream);
-        } else {
-            syn::parenthesized!(content in stream);
-        }
-
-        let mut body = Vec::new();
-        let mut children = Vec::new();
-        let mut manual_props = None;
-
-        while !content.is_empty() {
-            // if we splat into a component then we're merging properties
-            if content.peek(Token![..]) {
-                content.parse::<Token![..]>()?;
-                manual_props = Some(content.parse::<Expr>()?);
-            } else if content.peek(Ident) && content.peek2(Token![:]) && !content.peek3(Token![:]) {
-                body.push(content.parse::<ComponentField>()?);
-            } else {
-                children.push(content.parse::<BodyNode>()?);
-            }
-
-            if content.peek(Token![,]) {
-                let _ = content.parse::<Token![,]>();
-            }
-        }
-
-        Ok(Self {
-            name,
-            body,
-            children,
-            manual_props,
-        })
-    }
-}
-
-impl ToTokens for Component {
-    fn to_tokens(&self, tokens: &mut TokenStream2) {
-        let name = &self.name;
-
-        let mut has_key = None;
-
-        let builder = match &self.manual_props {
-            Some(manual_props) => {
-                let mut toks = quote! {
-                    let mut __manual_props = #manual_props;
-                };
-                for field in &self.body {
-                    if field.name == "key" {
-                        has_key = Some(field);
-                    } else {
-                        let name = &field.name;
-                        let val = &field.content;
-                        toks.append_all(quote! {
-                            __manual_props.#name = #val;
-                        });
-                    }
-                }
-                toks.append_all(quote! {
-                    __manual_props
-                });
-                quote! {{
-                    #toks
-                }}
-            }
-            None => {
-                let mut toks = quote! { fc_to_builder(#name) };
-                for field in &self.body {
-                    match field.name.to_string().as_str() {
-                        "key" => {
-                            //
-                            has_key = Some(field);
-                        }
-                        _ => toks.append_all(quote! {#field}),
-                    }
-                }
-
-                if !self.children.is_empty() {
-                    let childs = &self.children;
-                    toks.append_all(quote! {
-                        .children(__cx.create_children([ #( #childs ),* ]))
-                    });
-                }
-
-                toks.append_all(quote! {
-                    .build()
-                });
-                toks
-            }
-        };
-
-        let key_token = match has_key {
-            Some(field) => {
-                let inners = &field.content;
-                quote! { Some(format_args_f!(#inners)) }
-            }
-            None => quote! { None },
-        };
-
-        let fn_name = self.name.segments.last().unwrap().ident.to_string();
-
-        tokens.append_all(quote! {
-            __cx.component(
-                #name,
-                #builder,
-                #key_token,
-                #fn_name
-            )
-        })
-    }
-}
-
-// the struct's fields info
-pub struct ComponentField {
-    name: Ident,
-    content: ContentField,
-}
-
-enum ContentField {
-    ManExpr(Expr),
-    Formatted(LitStr),
-    OnHandlerRaw(Expr),
-}
-
-impl ToTokens for ContentField {
-    fn to_tokens(&self, tokens: &mut TokenStream2) {
-        match self {
-            ContentField::ManExpr(e) => e.to_tokens(tokens),
-            ContentField::Formatted(s) => tokens.append_all(quote! {
-                __cx.raw_text(format_args_f!(#s)).0
-            }),
-            ContentField::OnHandlerRaw(e) => tokens.append_all(quote! {
-                __cx.event_handler(#e)
-            }),
-        }
-    }
-}
-
-impl Parse for ComponentField {
-    fn parse(input: ParseStream) -> Result<Self> {
-        let name = Ident::parse_any(input)?;
-        input.parse::<Token![:]>()?;
-
-        if name.to_string().starts_with("on") {
-            let content = ContentField::OnHandlerRaw(input.parse()?);
-            return Ok(Self { name, content });
-        }
-
-        if name == "key" {
-            let content = ContentField::ManExpr(input.parse()?);
-            return Ok(Self { name, content });
-        }
-
-        if input.peek(LitStr) && input.peek2(Token![,]) {
-            let t: LitStr = input.fork().parse()?;
-
-            if is_literal_foramtted(&t) {
-                let content = ContentField::Formatted(input.parse()?);
-                return Ok(Self { name, content });
-            }
-        }
-
-        if input.peek(LitStr) && input.peek2(LitStr) {
-            let item = input.parse::<LitStr>().unwrap();
-            proc_macro_error::emit_error!(item, "This attribute is missing a trailing comma")
-        }
-
-        let content = ContentField::ManExpr(input.parse()?);
-        Ok(Self { name, content })
-    }
-}
-
-impl ToTokens for ComponentField {
-    fn to_tokens(&self, tokens: &mut TokenStream2) {
-        let ComponentField { name, content, .. } = self;
-        tokens.append_all(quote! {
-            .#name(#content)
-        })
-    }
-}
-
-fn is_literal_foramtted(lit: &LitStr) -> bool {
-    let s = lit.value();
-    let mut chars = s.chars();
-
-    while let Some(next) = chars.next() {
-        if next == '{' {
-            let nen = chars.next();
-            if nen != Some('{') {
-                return true;
-            }
-        }
-    }
-
-    false
-}

packages/rsx/src/element.rs

@@ -1,282 +0,0 @@
-use super::*;
-
-use proc_macro2::TokenStream as TokenStream2;
-use quote::{quote, ToTokens, TokenStreamExt};
-use syn::{
-    parse::{Parse, ParseBuffer, ParseStream},
-    Expr, Ident, LitStr, Result, Token,
-};
-
-// =======================================
-// Parse the VNode::Element type
-// =======================================
-pub struct Element {
-    pub name: Ident,
-    pub key: Option<LitStr>,
-    pub attributes: Vec<ElementAttrNamed>,
-    pub children: Vec<BodyNode>,
-    pub _is_static: bool,
-}
-
-impl Parse for Element {
-    fn parse(stream: ParseStream) -> Result<Self> {
-        let el_name = Ident::parse(stream)?;
-
-        // parse the guts
-        let content: ParseBuffer;
-        syn::braced!(content in stream);
-
-        let mut attributes: Vec<ElementAttrNamed> = vec![];
-        let mut children: Vec<BodyNode> = vec![];
-        let mut key = None;
-        let mut _el_ref = None;
-
-        // parse fields with commas
-        // break when we don't get this pattern anymore
-        // start parsing bodynodes
-        // "def": 456,
-        // abc: 123,
-        loop {
-            // Parse the raw literal fields
-            if content.peek(LitStr) && content.peek2(Token![:]) && !content.peek3(Token![:]) {
-                let name = content.parse::<LitStr>()?;
-                let ident = name.clone();
-
-                content.parse::<Token![:]>()?;
-
-                if content.peek(LitStr) && content.peek2(Token![,]) {
-                    let value = content.parse::<LitStr>()?;
-                    attributes.push(ElementAttrNamed {
-                        el_name: el_name.clone(),
-                        attr: ElementAttr::CustomAttrText { name, value },
-                    });
-                } else {
-                    let value = content.parse::<Expr>()?;
-
-                    attributes.push(ElementAttrNamed {
-                        el_name: el_name.clone(),
-                        attr: ElementAttr::CustomAttrExpression { name, value },
-                    });
-                }
-
-                if content.is_empty() {
-                    break;
-                }
-
-                // todo: add a message saying you need to include commas between fields
-                if content.parse::<Token![,]>().is_err() {
-                    proc_macro_error::emit_error!(
-                        ident,
-                        "This attribute is missing a trailing comma"
-                    )
-                }
-                continue;
-            }
-
-            if content.peek(Ident) && content.peek2(Token![:]) && !content.peek3(Token![:]) {
-                let name = content.parse::<Ident>()?;
-                let ident = name.clone();
-
-                let name_str = name.to_string();
-                content.parse::<Token![:]>()?;
-
-                if name_str.starts_with("on") {
-                    attributes.push(ElementAttrNamed {
-                        el_name: el_name.clone(),
-                        attr: ElementAttr::EventTokens {
-                            name,
-                            tokens: content.parse()?,
-                        },
-                    });
-                } else {
-                    match name_str.as_str() {
-                        "key" => {
-                            key = Some(content.parse()?);
-                        }
-                        "classes" => todo!("custom class list not supported yet"),
-                        // "namespace" => todo!("custom namespace not supported yet"),
-                        "node_ref" => {
-                            _el_ref = Some(content.parse::<Expr>()?);
-                        }
-                        _ => {
-                            if content.peek(LitStr) {
-                                attributes.push(ElementAttrNamed {
-                                    el_name: el_name.clone(),
-                                    attr: ElementAttr::AttrText {
-                                        name,
-                                        value: content.parse()?,
-                                    },
-                                });
-                            } else {
-                                attributes.push(ElementAttrNamed {
-                                    el_name: el_name.clone(),
-                                    attr: ElementAttr::AttrExpression {
-                                        name,
-                                        value: content.parse()?,
-                                    },
-                                });
-                            }
-                        }
-                    }
-                }
-
-                if content.is_empty() {
-                    break;
-                }
-
-                // todo: add a message saying you need to include commas between fields
-                if content.parse::<Token![,]>().is_err() {
-                    proc_macro_error::emit_error!(
-                        ident,
-                        "This attribute is missing a trailing comma"
-                    )
-                }
-                continue;
-            }
-
-            break;
-        }
-
-        while !content.is_empty() {
-            if (content.peek(LitStr) && content.peek2(Token![:])) && !content.peek3(Token![:]) {
-                let ident = content.parse::<LitStr>().unwrap();
-                let name = ident.value();
-                proc_macro_error::emit_error!(
-                    ident, "This attribute `{}` is in the wrong place.", name;
-                    help =
-"All attribute fields must be placed above children elements.
-
-                div {
-                   attr: \"...\",  <---- attribute is above children
-                   div { }       <---- children are below attributes
-                }";
-                )
-            }
-
-            if (content.peek(Ident) && content.peek2(Token![:])) && !content.peek3(Token![:]) {
-                let ident = content.parse::<Ident>().unwrap();
-                let name = ident.to_string();
-                proc_macro_error::emit_error!(
-                    ident, "This attribute `{}` is in the wrong place.", name;
-                    help =
-"All attribute fields must be placed above children elements.
-
-                div {
-                   attr: \"...\",  <---- attribute is above children
-                   div { }       <---- children are below attributes
-                }";
-                )
-            }
-
-            children.push(content.parse::<BodyNode>()?);
-            // consume comma if it exists
-            // we don't actually care if there *are* commas after elements/text
-            if content.peek(Token![,]) {
-                let _ = content.parse::<Token![,]>();
-            }
-        }
-
-        Ok(Self {
-            key,
-            name: el_name,
-            attributes,
-            children,
-            _is_static: false,
-        })
-    }
-}
-
-impl ToTokens for Element {
-    fn to_tokens(&self, tokens: &mut TokenStream2) {
-        let name = &self.name;
-        let children = &self.children;
-
-        let key = match &self.key {
-            Some(ty) => quote! { Some(format_args_f!(#ty)) },
-            None => quote! { None },
-        };
-
-        let listeners = self
-            .attributes
-            .iter()
-            .filter(|f| matches!(f.attr, ElementAttr::EventTokens { .. }));
-
-        let attr = self
-            .attributes
-            .iter()
-            .filter(|f| !matches!(f.attr, ElementAttr::EventTokens { .. }));
-
-        tokens.append_all(quote! {
-            __cx.element(
-                dioxus_elements::#name,
-                __cx.bump().alloc([ #(#listeners),* ]),
-                __cx.bump().alloc([ #(#attr),* ]),
-                __cx.bump().alloc([ #(#children),* ]),
-                #key,
-            )
-        });
-    }
-}
-
-pub enum ElementAttr {
-    /// attribute: "valuee {}"
-    AttrText { name: Ident, value: LitStr },
-
-    /// attribute: true,
-    AttrExpression { name: Ident, value: Expr },
-
-    /// "attribute": "value {}"
-    CustomAttrText { name: LitStr, value: LitStr },
-
-    /// "attribute": true,
-    CustomAttrExpression { name: LitStr, value: Expr },
-
-    // /// onclick: move |_| {}
-    // EventClosure { name: Ident, closure: ExprClosure },
-    /// onclick: {}
-    EventTokens { name: Ident, tokens: Expr },
-}
-
-pub struct ElementAttrNamed {
-    pub el_name: Ident,
-    pub attr: ElementAttr,
-}
-
-impl ToTokens for ElementAttrNamed {
-    fn to_tokens(&self, tokens: &mut TokenStream2) {
-        let ElementAttrNamed { el_name, attr } = self;
-
-        tokens.append_all(match attr {
-            ElementAttr::AttrText { name, value } => {
-                quote! {
-                    dioxus_elements::#el_name.#name(__cx, format_args_f!(#value))
-                }
-            }
-            ElementAttr::AttrExpression { name, value } => {
-                quote! {
-                    dioxus_elements::#el_name.#name(__cx, #value)
-                }
-            }
-            ElementAttr::CustomAttrText { name, value } => {
-                quote! {
-                    __cx.attr( #name, format_args_f!(#value), None, false )
-                }
-            }
-            ElementAttr::CustomAttrExpression { name, value } => {
-                quote! {
-                    __cx.attr( #name, format_args_f!(#value), None, false )
-                }
-            }
-            // ElementAttr::EventClosure { name, closure } => {
-            //     quote! {
-            //         dioxus_elements::on::#name(__cx, #closure)
-            //     }
-            // }
-            ElementAttr::EventTokens { name, tokens } => {
-                quote! {
-                    dioxus_elements::on::#name(__cx, #tokens)
-                }
-            }
-        });
-    }
-}

packages/rsx/src/lib.rs

@@ -1,97 +0,0 @@
-//! Parse the root tokens in the rsx!{} macro
-//! =========================================
-//!
-//! This parsing path emerges directly from the macro call, with `RsxRender` being the primary entrance into parsing.
-//! This feature must support:
-//! - [x] Optionally rendering if the `in XYZ` pattern is present
-//! - [x] Fragments as top-level element (through ambiguous)
-//! - [x] Components as top-level element (through ambiguous)
-//! - [x] Tags as top-level elements (through ambiguous)
-//! - [x] Good errors if parsing fails
-//!
-//! Any errors in using rsx! will likely occur when people start using it, so the first errors must be really helpful.
-
-mod component;
-mod element;
-mod node;
-
-pub mod pretty;
-
-// Re-export the namespaces into each other
-pub use component::*;
-pub use element::*;
-pub use node::*;
-
-// imports
-use proc_macro2::TokenStream as TokenStream2;
-use quote::{quote, ToTokens, TokenStreamExt};
-use syn::{
-    parse::{Parse, ParseStream},
-    Ident, Result, Token,
-};
-
-pub struct CallBody {
-    pub custom_context: Option<Ident>,
-    pub roots: Vec<BodyNode>,
-}
-
-impl Parse for CallBody {
-    fn parse(input: ParseStream) -> Result<Self> {
-        let custom_context = if input.peek(Ident) && input.peek2(Token![,]) {
-            let name = input.parse::<Ident>()?;
-            input.parse::<Token![,]>()?;
-
-            Some(name)
-        } else {
-            None
-        };
-
-        let mut roots = Vec::new();
-
-        while !input.is_empty() {
-            let node = input.parse::<BodyNode>()?;
-
-            if input.peek(Token![,]) {
-                let _ = input.parse::<Token![,]>();
-            }
-
-            roots.push(node);
-        }
-
-        Ok(Self {
-            custom_context,
-            roots,
-        })
-    }
-}
-
-/// Serialize the same way, regardless of flavor
-impl ToTokens for CallBody {
-    fn to_tokens(&self, out_tokens: &mut TokenStream2) {
-        let inner = if self.roots.len() == 1 {
-            let inner = &self.roots[0];
-            quote! { #inner }
-        } else {
-            let childs = &self.roots;
-            quote! { __cx.fragment_root([ #(#childs),* ]) }
-        };
-
-        match &self.custom_context {
-            // The `in cx` pattern allows directly rendering
-            Some(ident) => out_tokens.append_all(quote! {
-                #ident.render(LazyNodes::new(move |__cx: NodeFactory| -> VNode {
-                    use dioxus_elements::{GlobalAttributes, SvgAttributes};
-                    #inner
-                }))
-            }),
-
-            // Otherwise we just build the LazyNode wrapper
-            None => out_tokens.append_all(quote! {
-                LazyNodes::new(move |__cx: NodeFactory| -> VNode {
-                    use dioxus_elements::{GlobalAttributes, SvgAttributes};
-                    #inner
-                })
-            }),
-        };
-    }
-}

packages/rsx/src/node.rs

@@ -1,86 +0,0 @@
-use super::*;
-
-use proc_macro2::TokenStream as TokenStream2;
-use quote::{quote, ToTokens, TokenStreamExt};
-use syn::{
-    parse::{Parse, ParseStream},
-    token, Attribute, Expr, LitStr, Result, Token,
-};
-
-/*
-Parse
--> div {}
--> Component {}
--> component()
--> "text {with_args}"
--> (0..10).map(|f| rsx!("asd")),  // <--- notice the comma - must be a complete expr
-*/
-pub enum BodyNode {
-    Element(Element),
-    Component(Component),
-    Text(LitStr),
-    RawExpr(Expr),
-    Meta(Attribute),
-}
-
-impl Parse for BodyNode {
-    fn parse(stream: ParseStream) -> Result<Self> {
-        if stream.peek(LitStr) {
-            return Ok(BodyNode::Text(stream.parse()?));
-        }
-
-        // div {} -> el
-        // Div {} -> comp
-        if stream.peek(syn::Ident) && stream.peek2(token::Brace) {
-            if stream
-                .fork()
-                .parse::<Ident>()?
-                .to_string()
-                .chars()
-                .next()
-                .unwrap()
-                .is_ascii_uppercase()
-            {
-                return Ok(BodyNode::Component(stream.parse()?));
-            } else {
-                return Ok(BodyNode::Element(stream.parse::<Element>()?));
-            }
-        }
-
-        // component() -> comp
-        // ::component {} -> comp
-        // ::component () -> comp
-        if (stream.peek(syn::Ident) && stream.peek2(token::Paren))
-            || (stream.peek(Token![::]))
-            || (stream.peek(Token![:]) && stream.peek2(Token![:]))
-        {
-            return Ok(BodyNode::Component(stream.parse::<Component>()?));
-        }
-
-        // crate::component{} -> comp
-        // crate::component() -> comp
-        if let Ok(pat) = stream.fork().parse::<syn::Path>() {
-            if pat.segments.len() > 1 {
-                return Ok(BodyNode::Component(stream.parse::<Component>()?));
-            }
-        }
-
-        Ok(BodyNode::RawExpr(stream.parse::<Expr>()?))
-    }
-}
-
-impl ToTokens for BodyNode {
-    fn to_tokens(&self, tokens: &mut TokenStream2) {
-        match &self {
-            BodyNode::Element(el) => el.to_tokens(tokens),
-            BodyNode::Component(comp) => comp.to_tokens(tokens),
-            BodyNode::Text(txt) => tokens.append_all(quote! {
-                __cx.text(format_args_f!(#txt))
-            }),
-            BodyNode::RawExpr(exp) => tokens.append_all(quote! {
-                 __cx.fragment_from_iter(#exp)
-            }),
-            BodyNode::Meta(_) => {}
-        }
-    }
-}

packages/rsx/src/pretty.rs

@@ -1 +0,0 @@
-//! pretty printer for rsx!