RUST-333 Improve invalid URI option error message (#167)

Author: isabelatkinson

Cargo.toml

@@ -37,6 +37,7 @@ serde_with = "1.3.1"
 sha-1 = "0.8.1"
 sha2 = "0.8.0"
 stringprep = "0.1.2"
+strsim = "0.10.0"
 time = "0.1.42"
 trust-dns-proto = "0.19.4"
 trust-dns-resolver = "0.19.0"

src/client/options/mod.rs

@@ -23,6 +23,7 @@ use rustls::{
     ServerCertVerifier,
     TLSError,
 };
+use strsim::jaro_winkler;
 use typed_builder::TypedBuilder;
 use webpki_roots::TLS_SERVER_ROOTS;
 
@@ -38,6 +39,41 @@ use crate::{
 
 const DEFAULT_PORT: u16 = 27017;
 
+const URI_OPTIONS: &[&str] = &[
+    "appname",
+    "authmechanism",
+    "authsource",
+    "authmechanismproperties",
+    "compressors",
+    "connecttimeoutms",
+    "directconnection",
+    "heartbeatfrequencyms",
+    "journal",
+    "localthresholdms",
+    "maxidletimems",
+    "maxstalenessseconds",
+    "maxpoolsize",
+    "minpoolsize",
+    "readconcernlevel",
+    "readpreference",
+    "readpreferencetags",
+    "replicaset",
+    "retrywrites",
+    "retryreads",
+    "serverselectiontimeoutms",
+    "sockettimeoutms",
+    "tls",
+    "ssl",
+    "tlsinsecure",
+    "tlsallowinvalidcertificates",
+    "tlscafile",
+    "tlscertificatekeyfile",
+    "w",
+    "waitqueuetimeoutms",
+    "wtimeoutms",
+    "zlibcompressionlevel",
+];
+
 lazy_static! {
     /// Reserved characters as defined by [Section 2.2 of RFC-3986](https://tools.ietf.org/html/rfc3986#section-2.2).
     /// Usernames / passwords that contain these characters must instead include the URL encoded version of them when included
@@ -1393,11 +1429,22 @@ impl ClientOptionsParser {
                 self.zlib_compression = Some(i);
             }
 
-            _ => {
-                return Err(ErrorKind::ArgumentError {
-                    message: "invalid option warning".to_string(),
+            other => {
+                let (jaro_winkler, option) = URI_OPTIONS.iter().fold((0.0, ""), |acc, option| {
+                    let jaro_winkler = jaro_winkler(option, other).abs();
+                    if jaro_winkler > acc.0 {
+                        return (jaro_winkler, option);
+                    }
+                    acc
+                });
+                let mut message = format!("{} is an invalid option", other);
+                if jaro_winkler >= 0.84 {
+                    message.push_str(&format!(
+                        ". An option with a similar name exists: {}",
+                        option
+                    ));
                 }
-                .into());
+                return Err(ErrorKind::ArgumentError { message: message }.into());
             }
         }
 

src/client/options/test.rs

@@ -3,7 +3,7 @@ use pretty_assertions::assert_eq;
 use serde::Deserialize;
 
 use crate::{
-    client::options::{ClientOptions, StreamAddress},
+    client::options::{ClientOptions, ClientOptionsParser, StreamAddress},
     error::ErrorKind,
     selection_criteria::{ReadPreference, SelectionCriteria},
     test::run_spec_test,
@@ -332,3 +332,37 @@ async fn run_uri_options_spec_tests() {
 async fn run_connection_string_spec_tests() {
     run_spec_test(&["connection-string"], run_test).await;
 }
+
+async fn parse_uri(option: &str, suggestion: Option<&str>) {
+    match ClientOptionsParser::parse(&format!("mongodb://host:27017/?{}=test", option))
+        .as_ref()
+        .map_err(|e| e.as_ref())
+    {
+        Ok(_) => panic!("expected error for option {}", option),
+        Err(ErrorKind::ArgumentError { message, .. }) => {
+            match suggestion {
+                Some(s) => assert!(message.contains(s)),
+                None => assert!(!message.contains("similar")),
+            };
+        }
+        Err(e) => panic!("expected ArgumentError, but got {:?}", e),
+    }
+}
+
+#[cfg_attr(feature = "tokio-runtime", tokio::test)]
+#[cfg_attr(feature = "async-std-runtime", async_std::test)]
+async fn parse_unknown_options() {
+    parse_uri("invalidoption", None).await;
+    parse_uri("x", None).await;
+    parse_uri("max", None).await;
+    parse_uri("tlstimeout", None).await;
+    parse_uri("waitqueuetimeout", Some("waitqueuetimeoutms")).await;
+    parse_uri("retry_reads", Some("retryreads")).await;
+    parse_uri("poolsize", Some("maxpoolsize")).await;
+    parse_uri(
+        "tlspermitinvalidcertificates",
+        Some("tlsallowinvalidcertificates"),
+    )
+    .await;
+    parse_uri("maxstalenessms", Some("maxstalenessseconds")).await;
+}