Fix compilation & warnings

backend-rust/step1-json-api/src/model.rs

@@ -11,12 +11,17 @@ pub fn add_post(message: String, username: String) -> AppResult<()> {
 }
 
 pub fn get_all_posts(offset: u32, count: u32) -> AppResult<String> {
-    log::info!("get all posts");
+    log::info!("get all posts {} {}", offset, count);
     Ok("[]".to_string())
 }
 
 pub fn get_posts_by_username(username: String, offset: u32, count: u32) -> AppResult<String> {
-    log::info!("get all posts by username {}", username);
+    log::info!(
+        "get all posts by username {} {} {}",
+        username,
+        offset,
+        count
+    );
     Ok("[]".to_string())
 }
 

backend-rust/step2-database-only/src/database.rs

@@ -4,12 +4,21 @@ use crate::sqlite;
 pub fn query(query: &str) -> AppResult<String> {
     let response = sqlite::call(query.as_bytes());
 
-    // Add more details to error message
-    String::from_utf8(response).map_err(|e| {
+    // Decode query result to a utf8 string
+    let result_str = std::str::from_utf8(&response);
+
+    // Log if there's an error
+    if result_str.is_err() {
         log::error!("unable to decode result from bytes: {:#x?}", response);
+    }
+
+    // Wrap error with a better message, and return Result
+    result_str
+        .map_err(|e| {
             err_msg(&format!(
                 "unable to decode result from bytes {:#x?}: {}",
-            query, e
+                response, e
             ))
         })
+        .map(|s| s.to_string())
 }

backend-rust/step3-finished-app/src/database.rs

@@ -4,12 +4,21 @@ use crate::sqlite;
 pub fn query(query: &str) -> AppResult<String> {
     let response = sqlite::call(query.as_bytes());
 
-    // Add more details to error message
-    String::from_utf8(response).map_err(|e| {
+    // Decode query result to a utf8 string
+    let result_str = std::str::from_utf8(&response);
+
+    // Log if there's an error
+    if result_str.is_err() {
         log::error!("unable to decode result from bytes: {:#x?}", response);
+    }
+
+    // Wrap error with a better message, and return Result
+    result_str
+        .map_err(|e| {
             err_msg(&format!(
                 "unable to decode result from bytes {:#x?}: {}",
-            query, e
+                response, e
             ))
         })
+        .map(|s| s.to_string())
 }