Example WASM module that reverse the text from HTTP request

README.md

@@ -1,11 +1,10 @@
-# Knative Sample Controller
+# Knative WASM
 
 [![GoDoc](https://godoc.org/github.com/cardil/knative-serving-wasm?status.svg)](https://godoc.org/github.com/cardil/knative-serving-wasm)
 [![Go Report Card](https://goreportcard.com/badge/cardil/knative-serving-wasm)](https://goreportcard.com/report/cardil/knative-serving-wasm)
 
-Knative `knative-serving-wasm` defines a few simple resources that are validated by
-webhook and managed by a controller to demonstrate the canonical style in which
-Knative writes controllers.
+The `knative-serving-wasm` allows to run WASM modules that implement the
+[wasi-http](https://github.com/WebAssembly/wasi-http) interface on Kubernetes.
 
 To learn more about Knative, please visit our
 [Knative docs](https://github.com/knative/docs) repository.

examples/modules/reverse-text/Cargo.toml

@@ -6,7 +6,8 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-querystring = "1.1.0"
+querystring = "1.1"
+urlencoding = "2.1"
 
 [dependencies.wasi]
 git = "https://github.com/bytecodealliance/wasi"

examples/modules/reverse-text/src/lib.rs

@@ -27,24 +27,49 @@ impl exports::wasi::http::incoming_handler::Guest for Reverse {
 }
 
 /**
-  Get query parameter named "text", or return "Hello, WASI!" if
-  it's not present
-*/
+Get query parameter named "text", or return "Hello, WASI!" if
+it's not present
+ */
 fn fetch_text_query_param(pq: String) -> String {
-    pq.split_once("?")
+    urlencoding::decode(&pq)
+        .unwrap()
+        .split_once("?")
         .and_then(|(_, s)| {
-            return Some(querystring::querify(s))
+            return Some(querystring::querify(s));
         })
         .map(|q| {
             HashMap::from_iter(q)
         })
-        .map(|q| {
-            q.get("text")
+        .and_then(|q: HashMap<&str, &str>| {
+            q.get("text").cloned()
         })
-        .unwrap_or(Some("Hello, WASI!".to_string()))
-        .unwrap()
+        .map(|s| {
+            s.to_string()
+        })
+        .unwrap_or("Hello, WASI!".to_string())
 }
 
 fn reverse_text(str: String) -> String {
     str.chars().rev().collect()
-}
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_fetch_text_query_param() {
+        assert_eq!(fetch_text_query_param("".to_string()), "Hello, WASI!");
+        assert_eq!(fetch_text_query_param("?".to_string()), "Hello, WASI!");
+        assert_eq!(fetch_text_query_param("?text=Hello".to_string()), "Hello");
+        assert_eq!(fetch_text_query_param("?text=Happy%20testing".to_string()), "Happy testing");
+    }
+
+    #[test]
+    fn test_reverse_text() {
+        assert_eq!(reverse_text("".to_string()), "");
+        assert_eq!(reverse_text("a".to_string()), "a");
+        assert_eq!(reverse_text("ab".to_string()), "ba");
+        assert_eq!(reverse_text("abc".to_string()), "cba");
+    }
+}