Put all of serde behind feature flag

This commit makes the "serde" dependency completely optional.

Related: parcel-bundler#357

Cargo.toml

@@ -32,10 +32,10 @@ browserslist = ["browserslist-rs"]
 bundler = ["dashmap", "rayon"]
 cli = ["clap", "serde_json", "browserslist", "jemallocator"]
 grid = []
-serde = ["smallvec/serde", "cssparser/serde"]
+with-serde = ["serde", "smallvec/serde", "cssparser/serde"]
 
 [dependencies]
-serde = { version = "1.0.123", features = ["derive"] }
+serde = { version = "1.0.123", features = ["derive"], optional = true }
 cssparser = "0.29.1"
 parcel_selectors = { version = "0.24.9", path = "./selectors" }
 itertools = "0.10.1"

selectors/parser.rs

@@ -2709,7 +2709,7 @@ pub mod tests {
   use super::*;
   use crate::builder::SelectorFlags;
   use crate::parser;
-  use cssparser::{serialize_identifier, Parser as CssParser, ParserInput, ToCss, serialize_string};
+  use cssparser::{serialize_identifier, serialize_string, Parser as CssParser, ParserInput, ToCss};
   use std::collections::HashMap;
   use std::fmt;
 

src/bundler.rs

@@ -52,7 +52,6 @@ use cssparser::AtRuleParser;
 use dashmap::DashMap;
 use parcel_sourcemap::SourceMap;
 use rayon::prelude::*;
-use serde::Serialize;
 use std::{
   collections::HashSet,
   fs,
@@ -144,7 +143,8 @@ impl Drop for FileProvider {
 }
 
 /// An error that could occur during bundling.
-#[derive(Debug, Serialize)]
+#[derive(Debug)]
+#[cfg_attr(feature = "serde", serde::Serialize)]
 pub enum BundleErrorKind<'i, T: std::error::Error> {
   /// A parser error occurred.
   ParserError(ParserError<'i>),
@@ -155,7 +155,7 @@ pub enum BundleErrorKind<'i, T: std::error::Error> {
   /// Unsupported media query boolean logic was encountered.
   UnsupportedMediaBooleanLogic,
   /// A custom resolver error.
-  ResolverError(#[serde(skip)] T),
+  ResolverError(#[cfg_attr(feature = "serde", serde(skip))] T),
 }
 
 impl<'i, T: std::error::Error> From<Error<ParserError<'i>>> for Error<BundleErrorKind<'i, T>> {

src/css_modules.rs

@@ -14,6 +14,7 @@ use crate::selector::SelectorList;
 use data_encoding::{Encoding, Specification};
 use lazy_static::lazy_static;
 use pathdiff::diff_paths;
+#[cfg(feature = "serde")]
 use serde::Serialize;
 use smallvec::{smallvec, SmallVec};
 use std::borrow::Cow;
@@ -164,8 +165,9 @@ pub enum Segment<'i> {
 /// A referenced name within a CSS module, e.g. via the `composes` property.
 ///
 /// See [CssModuleExport](CssModuleExport).
-#[derive(PartialEq, Debug, Clone, Serialize)]
-#[serde(tag = "type", rename_all = "lowercase")]
+#[derive(PartialEq, Debug, Clone)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
+#[cfg_attr(feature = "serde", serde(tag = "type", rename_all = "lowercase"))]
 pub enum CssModuleReference {
   /// A local reference.
   Local {
@@ -187,8 +189,9 @@ pub enum CssModuleReference {
 }
 
 /// An exported value from a CSS module.
-#[derive(PartialEq, Debug, Clone, Serialize)]
-#[serde(rename_all = "camelCase")]
+#[derive(PartialEq, Debug, Clone)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
+#[cfg_attr(feature = "serde", serde(rename_all = "camelCase"))]
 pub struct CssModuleExport {
   /// The local (compiled) name for this export.
   pub name: String,

src/dependencies.rs

@@ -15,6 +15,7 @@ use crate::traits::ToCss;
 use crate::values::url::Url;
 use crate::visitor::Visit;
 use cssparser::SourceLocation;
+#[cfg(feature = "serde")]
 use serde::Serialize;
 
 /// Options for `analyze_dependencies` in `PrinterOptions`.
@@ -25,8 +26,9 @@ pub struct DependencyOptions {
 }
 
 /// A dependency.
-#[derive(Serialize, Debug)]
-#[serde(tag = "type", rename_all = "lowercase")]
+#[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
+#[cfg_attr(feature = "serde", serde(tag = "type", rename_all = "lowercase"))]
 pub enum Dependency {
   /// An `@import` dependency.
   Import(ImportDependency),
@@ -35,7 +37,8 @@ pub enum Dependency {
 }
 
 /// An `@import` dependency.
-#[derive(Serialize, Debug)]
+#[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
 pub struct ImportDependency {
   /// The url to import.
   pub url: String,
@@ -87,7 +90,8 @@ impl ImportDependency {
 }
 
 /// A `url()` dependency.
-#[derive(Serialize, Debug)]
+#[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
 pub struct UrlDependency {
   /// The url of the dependency.
   pub url: String,
@@ -110,8 +114,9 @@ impl UrlDependency {
 }
 
 /// Represents the range of source code where a dependency was found.
-#[derive(Serialize, Debug)]
-#[serde(rename_all = "camelCase")]
+#[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
+#[cfg_attr(feature = "serde", serde(rename_all = "camelCase"))]
 pub struct SourceRange {
   /// The filename in which the dependency was found.
   pub file_path: String,
@@ -122,8 +127,8 @@ pub struct SourceRange {
 }
 
 /// A line and column position within a source file.
-#[derive(Serialize, Debug, Clone, Copy, PartialEq, Visit)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize))]
+#[derive(Debug, Clone, Copy, PartialEq, Visit)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct Location {
   /// The line number, starting from 1.
   pub line: u32,

src/error.rs

@@ -5,12 +5,13 @@ use crate::rules::Location;
 use crate::values::string::CowArcStr;
 use cssparser::{BasicParseErrorKind, ParseError, ParseErrorKind};
 use parcel_selectors::parser::SelectorParseErrorKind;
+#[cfg(feature = "serde")]
 use serde::Serialize;
 use std::fmt;
 
 /// An error with a source location.
-#[derive(Debug, PartialEq, Clone, Serialize)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize))]
+#[derive(Debug, PartialEq, Clone)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct Error<T> {
   /// The type of error that occurred.
   pub kind: T,
@@ -31,8 +32,8 @@ impl<T: fmt::Display> fmt::Display for Error<T> {
 impl<T: fmt::Display + fmt::Debug> std::error::Error for Error<T> {}
 
 /// A line and column location within a source file.
-#[derive(Debug, PartialEq, Clone, Serialize)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize))]
+#[derive(Debug, PartialEq, Clone)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct ErrorLocation {
   /// The filename in which the error occurred.
   pub filename: String,
@@ -60,8 +61,9 @@ impl fmt::Display for ErrorLocation {
 }
 
 /// A parser error.
-#[derive(Debug, PartialEq, Serialize, Clone)]
-#[serde(tag = "type", content = "value")]
+#[derive(Debug, PartialEq, Clone)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
+#[cfg_attr(feature = "serde", serde(tag = "type", content = "value"))]
 pub enum ParserError<'i> {
   /// An at rule body was invalid.
   AtRuleBodyInvalid,
@@ -90,7 +92,7 @@ pub enum ParserError<'i> {
   /// A `@namespace` rule was encountered after any rules besides `@charset`, `@import`, or `@layer`.
   UnexpectedNamespaceRule,
   /// An unexpected token was encountered.
-  UnexpectedToken(#[serde(skip)] Token<'i>),
+  UnexpectedToken(#[cfg_attr(feature = "serde", serde(skip))] Token<'i>),
   /// Maximum nesting depth was reached.
   MaximumNestingDepth,
 }
@@ -164,45 +166,46 @@ impl<'i> ParserError<'i> {
 }
 
 /// A selector parsing error.
-#[derive(Debug, PartialEq, Serialize, Clone)]
-#[serde(tag = "type", content = "value")]
+#[derive(Debug, PartialEq, Clone)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
+#[cfg_attr(feature = "serde", serde(tag = "type", content = "value"))]
 pub enum SelectorError<'i> {
   /// An unexpected token was found in an attribute selector.
-  BadValueInAttr(#[serde(skip)] Token<'i>),
+  BadValueInAttr(#[cfg_attr(feature = "serde", serde(skip))] Token<'i>),
   /// An unexpected token was found in a class selector.
-  ClassNeedsIdent(#[serde(skip)] Token<'i>),
+  ClassNeedsIdent(#[cfg_attr(feature = "serde", serde(skip))] Token<'i>),
   /// A dangling combinator was found.
   DanglingCombinator,
   /// An empty selector.
   EmptySelector,
   /// A `|` was expected in an attribute selector.
-  ExpectedBarInAttr(#[serde(skip)] Token<'i>),
+  ExpectedBarInAttr(#[cfg_attr(feature = "serde", serde(skip))] Token<'i>),
   /// A namespace was expected.
   ExpectedNamespace(CowArcStr<'i>),
   /// An unexpected token was encountered in a namespace.
-  ExplicitNamespaceUnexpectedToken(#[serde(skip)] Token<'i>),
+  ExplicitNamespaceUnexpectedToken(#[cfg_attr(feature = "serde", serde(skip))] Token<'i>),
   /// An invalid pseudo class was encountered after a pseudo element.
   InvalidPseudoClassAfterPseudoElement,
   /// An invalid pseudo class was encountered after a `-webkit-scrollbar` pseudo element.
   InvalidPseudoClassAfterWebKitScrollbar,
   /// A `-webkit-scrollbar` state was encountered before a `-webkit-scrollbar` pseudo element.
   InvalidPseudoClassBeforeWebKitScrollbar,
   /// Invalid qualified name in attribute selector.
-  InvalidQualNameInAttr(#[serde(skip)] Token<'i>),
+  InvalidQualNameInAttr(#[cfg_attr(feature = "serde", serde(skip))] Token<'i>),
   /// The current token is not allowed in this state.
   InvalidState,
   /// The selector is required to have the `&` nesting selector at the start.
   MissingNestingPrefix,
   /// The selector is missing a `&` nesting selector.
   MissingNestingSelector,
   /// No qualified name in attribute selector.
-  NoQualifiedNameInAttributeSelector(#[serde(skip)] Token<'i>),
+  NoQualifiedNameInAttributeSelector(#[cfg_attr(feature = "serde", serde(skip))] Token<'i>),
   /// An Invalid token was encountered in a pseudo element.
-  PseudoElementExpectedIdent(#[serde(skip)] Token<'i>),
+  PseudoElementExpectedIdent(#[cfg_attr(feature = "serde", serde(skip))] Token<'i>),
   /// An unexpected identifier was encountered.
   UnexpectedIdent(CowArcStr<'i>),
   /// An unexpected token was encountered inside an attribute selector.
-  UnexpectedTokenInAttributeSelector(#[serde(skip)] Token<'i>),
+  UnexpectedTokenInAttributeSelector(#[cfg_attr(feature = "serde", serde(skip))] Token<'i>),
   /// An unsupported pseudo class or pseudo element was encountered.
   UnsupportedPseudoClassOrElement(CowArcStr<'i>),
 }
@@ -291,8 +294,9 @@ impl<T: fmt::Display + fmt::Debug> std::error::Error for ErrorWithLocation<T> {}
 pub(crate) type MinifyError = ErrorWithLocation<MinifyErrorKind>;
 
 /// A transformation error.
-#[derive(Debug, PartialEq, Serialize)]
-#[serde(tag = "type")]
+#[derive(Debug, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
+#[cfg_attr(feature = "serde", serde(tag = "type"))]
 pub enum MinifyErrorKind {
   /// A circular `@custom-media` rule was detected.
   CircularCustomMedia {
@@ -337,8 +341,9 @@ impl MinifyErrorKind {
 pub type PrinterError = Error<PrinterErrorKind>;
 
 /// A printer error type.
-#[derive(Debug, PartialEq, Serialize)]
-#[serde(tag = "type")]
+#[derive(Debug, PartialEq)]
+#[cfg_attr(feature = "serde", Serialize)]
+#[cfg_attr(feature = "serde", serde(tag = "type"))]
 pub enum PrinterErrorKind {
   /// An ambiguous relative `url()` was encountered in a custom property declaration.
   AmbiguousUrlInCustomProperty {

src/rules/mod.rs

@@ -85,6 +85,7 @@ use media::MediaRule;
 use namespace::NamespaceRule;
 use nesting::NestingRule;
 use page::PageRule;
+#[cfg(feature = "serde")]
 use serde::Serialize;
 use std::collections::{HashMap, HashSet};
 use style::StyleRule;
@@ -108,8 +109,8 @@ pub(crate) struct StyleContext<'a, 'i, T> {
 }
 
 /// A source location.
-#[derive(PartialEq, Eq, Debug, Clone, Copy, Serialize)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize))]
+#[derive(PartialEq, Eq, Debug, Clone, Copy)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct Location {
   /// The index of the source file within the source map.
   pub source_index: u32,

src/targets.rs

@@ -1,6 +1,7 @@
 //! Browser target options.
 // This file is autogenerated by build-prefixes.js. DO NOT EDIT!
 
+#[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
 /// Browser versions to compile CSS for.
@@ -20,7 +21,8 @@ use serde::{Deserialize, Serialize};
 ///   ..Browsers::default()
 /// };
 /// ```
-#[derive(Serialize, Debug, Deserialize, Clone, Copy, Default)]
+#[derive(Debug, Clone, Copy, Default)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[allow(missing_docs)]
 pub struct Browsers {
   pub android: Option<u32>,

src/values/string.rs

@@ -5,6 +5,7 @@ use crate::visitor::{Visit, VisitTypes, Visitor};
 use cssparser::{serialize_string, CowRcStr};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Deserializer};
+#[cfg(feature = "serde")]
 use serde::{Serialize, Serializer};
 use std::borrow::Borrow;
 use std::cmp;
@@ -219,6 +220,7 @@ impl<'a> fmt::Debug for CowArcStr<'a> {
   }
 }
 
+#[cfg(feature = "serde")]
 impl<'a> Serialize for CowArcStr<'a> {
   fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
     self.as_ref().serialize(serializer)