Test features individually

.github/workflows/msrv.yml

@@ -81,6 +81,37 @@ jobs:
           command: test
           args: --all-features
 
+  test-feature:
+    needs: [check]
+    name: Test Suite, only some features enabled
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - stable
+        feature:
+          - json
+          - yaml
+          - hjson
+          - ini
+          - json5
+          - preserve_order
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v2
+
+      - name: Install toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.rust }}
+          override: true
+
+      - name: Run cargo test ${{ matrix.feature }}
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --no-default-features --features ${{ matrix.feature }}
+
   fmt:
     needs: [check]
     name: Rustfmt

examples/async_source/main.rs

@@ -1,72 +1,84 @@
-use std::error::Error;
+#[cfg(feature = "json")]
+mod example {
+    use std::error::Error;
 
-use config::{builder::AsyncState, AsyncSource, ConfigBuilder, ConfigError, FileFormat, Map};
+    use config::{builder::AsyncState, AsyncSource, ConfigBuilder, ConfigError, FileFormat, Map};
 
-use async_trait::async_trait;
-use futures::{select, FutureExt};
-use warp::Filter;
+    use async_trait::async_trait;
+    use warp::Filter;
 
-// Example below presents sample configuration server and client.
-//
-// Server serves simple configuration on HTTP endpoint.
-// Client consumes it using custom HTTP AsyncSource built on top of reqwest.
+    // Example below presents sample configuration server and client.
+    //
+    // Server serves simple configuration on HTTP endpoint.
+    // Client consumes it using custom HTTP AsyncSource built on top of reqwest.
 
-#[tokio::main]
-async fn main() -> Result<(), Box<dyn Error>> {
-    select! {
-        r = run_server().fuse() => r,
-        r = run_client().fuse() => r
-    }
-}
 
-async fn run_server() -> Result<(), Box<dyn Error>> {
-    let service = warp::path("configuration").map(|| r#"{ "value" : 123 }"#);
+    pub async fn run_server() -> Result<(), Box<dyn Error>> {
+        let service = warp::path("configuration").map(|| r#"{ "value" : 123 }"#);
 
-    println!("Running server on localhost:5001");
+        println!("Running server on localhost:5001");
 
-    warp::serve(service).bind(([127, 0, 0, 1], 5001)).await;
+        warp::serve(service).bind(([127, 0, 0, 1], 5001)).await;
 
-    Ok(())
-}
+        Ok(())
+    }
 
-async fn run_client() -> Result<(), Box<dyn Error>> {
-    // Good enough for an example to allow server to start
-    tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
+    pub async fn run_client() -> Result<(), Box<dyn Error>> {
+        // Good enough for an example to allow server to start
+        tokio::time::sleep(tokio::time::Duration::from_secs(3)).await;
 
-    let config = ConfigBuilder::<AsyncState>::default()
-        .add_async_source(HttpSource {
-            uri: "http://localhost:5001/configuration".into(),
-            format: FileFormat::Json,
-        })
-        .build()
-        .await?;
+        let config = ConfigBuilder::<AsyncState>::default()
+            .add_async_source(HttpSource {
+                uri: "http://localhost:5001/configuration".into(),
+                format: FileFormat::Json,
+            })
+            .build()
+            .await?;
 
-    println!("Config value is {}", config.get::<String>("value")?);
+        println!("Config value is {}", config.get::<String>("value")?);
 
-    Ok(())
-}
+        Ok(())
+    }
 
-// Actual implementation of AsyncSource can be found below
+    // Actual implementation of AsyncSource can be found below
+
+    #[derive(Debug)]
+    struct HttpSource {
+        uri: String,
+        format: FileFormat,
+    }
+
+    #[async_trait]
+    impl AsyncSource for HttpSource {
+        async fn collect(&self) -> Result<Map<String, config::Value>, ConfigError> {
+            reqwest::get(&self.uri)
+                .await
+                .map_err(|e| ConfigError::Foreign(Box::new(e)))? // error conversion is possible from custom AsyncSource impls
+                .text()
+                .await
+                .map_err(|e| ConfigError::Foreign(Box::new(e)))
+                .and_then(|text| {
+                    self.format
+                        .parse(Some(&self.uri), &text)
+                        .map_err(|e| ConfigError::Foreign(e))
+                })
+        }
+    }
 
-#[derive(Debug)]
-struct HttpSource {
-    uri: String,
-    format: FileFormat,
 }
 
-#[async_trait]
-impl AsyncSource for HttpSource {
-    async fn collect(&self) -> Result<Map<String, config::Value>, ConfigError> {
-        reqwest::get(&self.uri)
-            .await
-            .map_err(|e| ConfigError::Foreign(Box::new(e)))? // error conversion is possible from custom AsyncSource impls
-            .text()
-            .await
-            .map_err(|e| ConfigError::Foreign(Box::new(e)))
-            .and_then(|text| {
-                self.format
-                    .parse(Some(&self.uri), &text)
-                    .map_err(|e| ConfigError::Foreign(e))
-            })
+#[cfg(feature = "json")]
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    use futures::{select, FutureExt};
+    select! {
+        r = example::run_server().fuse() => r,
+        r = example::run_client().fuse() => r
     }
 }
+
+#[cfg(not(feature = "json"))]
+fn main() {
+    println!("This example needs the 'json' feature enabled");
+}
+

src/builder.rs

@@ -34,44 +34,46 @@ use crate::{config::Config, path::Expression, source::Source, value::Value};
 ///
 /// # Examples
 ///
-/// ```rust
-/// # use config::*;
-/// # use std::error::Error;
-/// # fn main() -> Result<(), Box<dyn Error>> {
-/// let mut builder = Config::builder()
-///     .set_default("default", "1")?
-///     .add_source(File::new("config/settings", FileFormat::Json))
-/// //  .add_async_source(...)
-///     .set_override("override", "1")?;
-///
-/// match builder.build() {
-///     Ok(config) => {
-///         // use your config
-///     },
-///     Err(e) => {
-///         // something went wrong
-///     }
-/// }
-/// # Ok(())
-/// # }
-/// ```
-///
-/// If any [`AsyncSource`] is used, the builder will transition to [`AsyncState`].
-/// In such case, it is required to _await_ calls to [`build`](Self::build) and its non-consuming sibling.
-///
-/// Calls can be not chained as well
-/// ```rust
-/// # use std::error::Error;
-/// # use config::*;
-/// # fn main() -> Result<(), Box<dyn Error>> {
-/// let mut builder = Config::builder();
-/// builder = builder.set_default("default", "1")?;
-/// builder = builder.add_source(File::new("config/settings", FileFormat::Json));
-/// builder = builder.add_source(File::new("config/settings.prod", FileFormat::Json));
-/// builder = builder.set_override("override", "1")?;
-/// # Ok(())
-/// # }
-/// ```
+#[cfg_attr(feature = "feature", doc = r##"
+```rust
+# use config::*;
+# use std::error::Error;
+# fn main() -> Result<(), Box<dyn Error>> {
+let mut builder = Config::builder()
+    .set_default("default", "1")?
+    .add_source(File::new("config/settings", FileFormat::Json))
+//  .add_async_source(...)
+    .set_override("override", "1")?;
+
+match builder.build() {
+    Ok(config) => {
+        // use your config
+    },
+    Err(e) => {
+        // something went wrong
+    }
+}
+# Ok(())
+# }
+```
+
+If any [`AsyncSource`] is used, the builder will transition to [`AsyncState`].
+In such case, it is required to _await_ calls to [`build`](Self::build) and its non-consuming sibling.
+
+Calls can be not chained as well
+```rust
+# use std::error::Error;
+# use config::*;
+# fn main() -> Result<(), Box<dyn Error>> {
+let mut builder = Config::builder();
+builder = builder.set_default("default", "1")?;
+builder = builder.add_source(File::new("config/settings", FileFormat::Json));
+builder = builder.add_source(File::new("config/settings.prod", FileFormat::Json));
+builder = builder.set_override("override", "1")?;
+# Ok(())
+# }
+```
+"##)]
 ///
 /// Calling [`Config::builder`](Config::builder) yields builder in the default state.
 /// If having an asynchronous state as the initial state is desired, _turbofish_ notation needs to be used.

src/ser.rs

@@ -699,6 +699,9 @@ impl ser::SerializeStructVariant for StringKeySerializer {
 mod test {
     use super::*;
 
+    use serde_derive::Serialize;
+    use serde_derive::Deserialize;
+
     #[test]
     fn test_struct() {
         #[derive(Debug, Serialize, Deserialize, PartialEq)]

tests/async_builder.rs

@@ -46,6 +46,7 @@ impl AsyncSource for AsyncFile {
     }
 }
 
+#[cfg(feature = "json")]
 #[tokio::test]
 async fn test_single_async_file_source() {
     let config = Config::builder()
@@ -60,6 +61,7 @@ async fn test_single_async_file_source() {
     assert_eq!(true, config.get::<bool>("debug").unwrap());
 }
 
+#[cfg(all(feature = "json", feature = "toml"))]
 #[tokio::test]
 async fn test_two_async_file_sources() {
     let config = Config::builder()
@@ -80,6 +82,7 @@ async fn test_two_async_file_sources() {
     assert_eq!(1, config.get::<i32>("place.number").unwrap());
 }
 
+#[cfg(all(feature = "toml", feature = "json"))]
 #[tokio::test]
 async fn test_sync_to_async_file_sources() {
     let config = Config::builder()
@@ -96,6 +99,7 @@ async fn test_sync_to_async_file_sources() {
     assert_eq!(1, config.get::<i32>("place.number").unwrap());
 }
 
+#[cfg(all(feature = "toml", feature = "json"))]
 #[tokio::test]
 async fn test_async_to_sync_file_sources() {
     let config = Config::builder()
@@ -112,6 +116,7 @@ async fn test_async_to_sync_file_sources() {
     assert_eq!(1, config.get::<i32>("place.number").unwrap());
 }
 
+#[cfg(feature = "toml")]
 #[tokio::test]
 async fn test_async_file_sources_with_defaults() {
     let config = Config::builder()
@@ -132,6 +137,7 @@ async fn test_async_file_sources_with_defaults() {
     assert_eq!(1, config.get::<i32>("place.number").unwrap());
 }
 
+#[cfg(feature = "toml")]
 #[tokio::test]
 async fn test_async_file_sources_with_overrides() {
     let config = Config::builder()

tests/errors.rs

@@ -117,40 +117,20 @@ fn error_with_path() {
         inner: Inner,
     }
     const CFG: &str = r#"
-inner:
-    test: ABC
-"#;
+        inner.test = "ABC"
+    "#;
 
     let e = Config::builder()
-        .add_source(File::from_str(CFG, FileFormat::Yaml))
+        .add_source(File::from_str(CFG, FileFormat::Toml))
         .build()
         .unwrap()
         .try_into::<Outer>()
         .unwrap_err();
 
-    if let ConfigError::Type {
-        key: Some(path), ..
-    } = e
-    {
+    if let ConfigError::Type { key: Some(path), ..  } = e {
         assert_eq!(path, "inner.test");
     } else {
         panic!("Wrong error {:?}", e);
     }
 }
 
-#[test]
-fn test_error_root_not_table() {
-    match Config::builder()
-        .add_source(File::from_str(r#"false"#, FileFormat::Json5))
-        .build()
-    {
-        Ok(_) => panic!("Should not merge if root is not a table"),
-        Err(e) => match e {
-            ConfigError::FileParse { cause, .. } => assert_eq!(
-                "invalid type: boolean `false`, expected a map",
-                format!("{}", cause)
-            ),
-            _ => panic!("Wrong error: {:?}", e),
-        },
-    }
-}

tests/file_json5.rs

@@ -94,3 +94,20 @@ fn test_error_parse() {
         )
     );
 }
+
+#[test]
+fn test_error_root_not_table() {
+    match Config::builder()
+        .add_source(File::from_str(r#"false"#, FileFormat::Json5))
+        .build()
+    {
+        Ok(_) => panic!("Should not merge if root is not a table"),
+        Err(e) => match e {
+            ConfigError::FileParse { cause, .. } => assert_eq!(
+                "invalid type: boolean `false`, expected a map",
+                format!("{}", cause)
+            ),
+            _ => panic!("Wrong error: {:?}", e),
+        },
+    }
+}