Add js import codegen

backend/src/codegen.rs

@@ -13,7 +13,10 @@ pub trait Emit<W: Write> {
 }
 
 pub enum Statement {
-    Import,
+    Import {
+        names: Vec<String>,
+        from: String,
+    },
     Declaration {
         is_exported: bool,
         is_const: bool,
@@ -179,7 +182,16 @@ impl<W: Write> Emit<W> for Statement {
                 }
                 write!(w, "{}", "}").map_err(EmitError::WriterError)
             }
-            _ => todo!("Tehe"),
+            Statement::Import { names, from } => {
+                write!(w, "import {}", "{").map_err(EmitError::WriterError)?;
+                for (i, name) in names.iter().enumerate() {
+                    write!(w, "{}", name).map_err(EmitError::WriterError)?;
+                    if i + 1 != names.len() {
+                        write!(w, ", ").map_err(EmitError::WriterError)?;
+                    }
+                }
+                write!(w, "{} from {};", "}", from).map_err(EmitError::WriterError)
+            }
         }
     }
 }
@@ -636,3 +648,25 @@ fn if_emit() {
     if_.emit(&mut res).unwrap();
     assert_eq!(res, "if (true) {null} else {undefined}")
 }
+
+#[test]
+fn empty_import_emit() {
+    let import = Statement::Import {
+        names: Vec::new(),
+        from: "x".to_owned(),
+    };
+    let mut res = String::new();
+    import.emit(&mut res).unwrap();
+    assert_eq!(res, "import {} from x;")
+}
+
+#[test]
+fn import_emit() {
+    let import = Statement::Import {
+        names: vec!["x".to_owned(), "y".to_owned()],
+        from: "z".to_owned(),
+    };
+    let mut res = String::new();
+    import.emit(&mut res).unwrap();
+    assert_eq!(res, "import {x, y} from z;")
+}