feat: Make loading from local files be gated behind a feature as well.

The file loading machinery in `std` is also pretty large--it adds about
500 kB (or about 100 kB compressed) of file size. Like with loading external
URLs, this functionality can be unneeded in some applications (such as
with wasm binaries, which typically don't have file system access). Allowing
external file loading to be disabled avoids incurring this overhead.

Author: a2aaron

bindings/python/Cargo.toml

@@ -17,7 +17,7 @@ built = { version = "0.5", features = ["chrono"] }
 path = "../../css-inline"
 version = "*"
 default-features = false
-features = ["http"]
+features = ["http", "file"]
 
 [dependencies]
 url = "2"

bindings/wasm/Cargo.toml

@@ -20,7 +20,7 @@ crate-type = ["cdylib"]
 path = "../../css-inline"
 version = "*"
 default-features = false
-features = ["http"]
+features = ["http", "file"]
 
 [dependencies]
 url = "2"

css-inline/Cargo.toml

@@ -15,9 +15,10 @@ categories = ["web-programming"]
 name = "css-inline"
 
 [features]
-default = ["cli", "http"]
+default = ["cli", "http", "file"]
 cli = ["pico-args", "rayon"]
 http = ["attohttpc"]
+file = []
 
 [dependencies]
 cssparser = "0.29"

css-inline/src/lib.rs

@@ -40,7 +40,6 @@ use indexmap::IndexMap;
 use smallvec::{smallvec, SmallVec};
 use std::{
     borrow::Cow,
-    fs,
     io::{ErrorKind, Write},
 };
 
@@ -358,12 +357,22 @@ fn load_external(location: &str) -> Result<String> {
             )))
         }
     } else {
-        fs::read_to_string(location).map_err(|error| match error.kind() {
-            ErrorKind::NotFound => InlineError::MissingStyleSheet {
-                path: location.to_string(),
-            },
-            _ => InlineError::IO(error),
-        })
+        #[cfg(feature = "file")]
+        {
+            std::fs::read_to_string(location).map_err(|error| match error.kind() {
+                ErrorKind::NotFound => InlineError::MissingStyleSheet {
+                    path: location.to_string(),
+                },
+                _ => InlineError::IO(error),
+            })
+        }
+        #[cfg(not(feature = "file"))]
+        {
+            Err(InlineError::IO(std::io::Error::new(
+                ErrorKind::Unsupported,
+                "Loading local files requires the `file` feature",
+            )))
+        }
     }
 }