add tests for db.rs

.github/workflows/rust.yml

@@ -25,4 +25,4 @@ jobs:
     - name: Build
       run: cargo build --verbose
     - name: Run tests
-      run: cargo test --verbose
+      run: cd nevmes-core && cargo test --verbose

nevmes-core/src/db.rs

@@ -14,12 +14,18 @@ use log::{
 
 use crate::utils;
 
+/// LMDB Interface allows access to the env
+///
+/// and handle for the write, read and delete
+///
+/// functionality.
 pub struct Interface {
     pub env: Environment,
     pub handle: DbHandle,
 }
 
 impl Interface {
+    /// Instantiation of ```Environment``` and ```DbHandle```
     pub fn open() -> Self {
         let release_env = utils::get_release_env();
         let file_path = format!(
@@ -32,10 +38,13 @@ impl Interface {
         };
         let env = EnvBuilder::new()
             .open(format!("{}/{}", file_path, env_str), 0o777)
-            .unwrap();
+            .expect(&format!("could not open LMDB at {}", file_path));
         let handle = env.get_default_db(DbFlags::empty()).unwrap();
         Interface { env, handle }
     }
+    /// Write a key-value to LMDB. NEVMES does not currently support
+    ///
+    /// writing multiple key value pairs.
     pub fn write(e: &Environment, h: &DbHandle, k: &str, v: &str) {
         let txn = e.new_transaction().unwrap();
         {
@@ -51,6 +60,11 @@ impl Interface {
             Ok(_) => (),
         }
     }
+    /// Read a value from LMDB by passing the key as a static
+    ///
+    /// string. If the value does not exist an empty string is
+    ///
+    /// returned. NEVMES does not currently support duplicate keys.
     pub fn read(e: &Environment, h: &DbHandle, k: &str) -> String {
         let reader = e.get_reader().unwrap();
         let db = reader.bind(&h);
@@ -63,6 +77,11 @@ impl Interface {
         }
         r
     }
+    /// Delete a value from LMDB by passing the key as a
+    ///
+    /// static string. If the value does not exist then an
+    ///
+    /// error will be logged.
     pub fn delete(e: &Environment, h: &DbHandle, k: &str) {
         let txn = e.new_transaction().unwrap();
         {
@@ -76,3 +95,35 @@ impl Interface {
         }
     }
 }
+
+// Tests
+//-------------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn write_and_read_test() {
+        let s = Interface::open();
+        let k = "test-key";
+        let v = "test-value";
+        Interface::write(&s.env, &s.handle, k, v);
+        let expected = String::from(v);
+        let actual = Interface::read(&s.env, &s.handle, k);
+        assert_eq!(expected, actual);
+        Interface::delete(&s.env, &s.handle, &k);
+    }
+
+    #[test]
+    fn write_and_delete_test() {
+        let s = Interface::open();
+        let k = "test-key";
+        let v = "test-value";
+        Interface::write(&s.env, &s.handle, k, v);
+        let expected = utils::empty_string();
+        Interface::delete(&s.env, &s.handle, &k);
+        let actual = Interface::read(&s.env, &s.handle, k);
+        assert_eq!(expected, actual);
+    }
+}