Disable doc generation when AUTOMETRICS_DISABLE_DOCS env var is present (#104)

* Disable doc generation when AUTOMETRICS_DISABLE_DOCS env var is present

* Use env::var

Author: emschwartz

CHANGELOG.md

@@ -18,6 +18,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   Autometrics now provides a `tracing_subscriber::Layer` that makes the specific `Span` fields
   available to the library, and autometrics will automatically attach those fields as exemplars
   on the counter and histogram metrics
+- `AUTOMETRICS_DISABLE_DOCS` environment variable can be set to disable doc comment generation
+  (this is mainly for use with editor extensions that generate doc comments themselves)
 
 ### Changed
 

autometrics-macros/src/lib.rs

@@ -57,8 +57,12 @@ fn instrument_function(args: &AutometricsArgs, item: ItemFn) -> Result<TokenStre
     let prometheus_url =
         env::var("PROMETHEUS_URL").unwrap_or_else(|_| DEFAULT_PROMETHEUS_URL.to_string());
 
-    // Build the documentation we'll add to the function's RustDocs
-    let metrics_docs = create_metrics_docs(&prometheus_url, &function_name, args.track_concurrency);
+    // Build the documentation we'll add to the function's RustDocs, unless it is disabled by the environment variable
+    let metrics_docs = if env::var("AUTOMETRICS_DISABLE_DOCS").is_ok() {
+        String::new()
+    } else {
+        create_metrics_docs(&prometheus_url, &function_name, args.track_concurrency)
+    };
 
     // Type annotation to allow type inference to work on return expressions (such as `.collect()`), as
     // well as prevent compiler type-inference from selecting the wrong branch in the `spez` macro later.