Start a rust-based foreign document test.

Instead of using a simple bash script, this will use async rust to run multiple tests in parallel.

Cargo.toml

@@ -31,6 +31,12 @@ path = "src/lib.rs"
   path = "src/bin_compare.rs"
   required-features = ["compare"]
 
+[[bin]]
+  # This bin exists for development purposes only. The real target of this crate is the library.
+  name = "foreign_document_test"
+  path = "src/bin_foreign_document_test.rs"
+  required-features = ["foreign_document_test"]
+
 [dependencies]
 nom = "7.1.1"
 opentelemetry = { version = "0.20.0", optional = true, default-features = false, features = ["trace", "rt-tokio"] }
@@ -47,6 +53,7 @@ walkdir = "2.3.3"
 [features]
 default = []
 compare = []
+foreign_document_test = ["compare", "dep:tokio"]
 tracing = ["dep:opentelemetry", "dep:opentelemetry-otlp", "dep:opentelemetry-semantic-conventions", "dep:tokio", "dep:tracing", "dep:tracing-opentelemetry", "dep:tracing-subscriber"]
 
 # Optimized build for any sort of release.

src/bin_foreign_document_test.rs

@@ -0,0 +1,57 @@
+#![feature(round_char_boundary)]
+#![feature(exact_size_is_empty)]
+use std::io::Read;
+
+use organic::compare::run_anonymous_compare;
+use organic::compare::run_compare_on_file;
+
+#[cfg(feature = "tracing")]
+use crate::init_tracing::init_telemetry;
+#[cfg(feature = "tracing")]
+use crate::init_tracing::shutdown_telemetry;
+#[cfg(feature = "tracing")]
+mod init_tracing;
+
+#[cfg(not(feature = "tracing"))]
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let rt = tokio::runtime::Runtime::new()?;
+    let result = rt.block_on(async {
+        let main_body_result = main_body();
+        main_body_result
+    });
+    result
+}
+
+#[cfg(feature = "tracing")]
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let rt = tokio::runtime::Runtime::new()?;
+    let result = rt.block_on(async {
+        init_telemetry()?;
+        let main_body_result = main_body();
+        shutdown_telemetry()?;
+        main_body_result
+    });
+    result
+}
+
+#[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
+fn main_body() -> Result<(), Box<dyn std::error::Error>> {
+    let args = std::env::args().skip(1);
+    if args.is_empty() {
+        let org_contents = read_stdin_to_string()?;
+        run_anonymous_compare(org_contents)
+    } else {
+        for arg in args {
+            run_compare_on_file(arg)?
+        }
+        Ok(())
+    }
+}
+
+fn read_stdin_to_string() -> Result<String, Box<dyn std::error::Error>> {
+    let mut stdin_contents = String::new();
+    std::io::stdin()
+        .lock()
+        .read_to_string(&mut stdin_contents)?;
+    Ok(stdin_contents)
+}