Add option to write output to a file and fix minor TypeScript coding style & formatting issues.

README.md

@@ -4,6 +4,14 @@ json into beautiful typescript...until now.
 
 Noctilucent will take your json and output the equivalent typescript.
 
+## User Guide
+```
+cargo build --release
+./target/release/noctilucent <INPUT> <OUTPUT>
+```
+* `INPUT` is the input file path.
+* `OUTPUT` is the output file path; if not specified, output will be printed on your command line.
+
 ## Implemented
 
 - [x] Fn::FindInMap

src/main.rs

@@ -16,6 +16,12 @@ fn main() {
                 .required(true)
                 .index(1),
         )
+        .arg(
+            Arg::new("OUTPUT")
+                .help("Sets the output file to use")
+                .required(false)
+                .index(2),
+        )
         .get_matches();
 
     let txt_location: &str = matches.value_of("INPUT").unwrap();
@@ -24,5 +30,11 @@ fn main() {
 
     let cfn_tree = CloudformationParseTree::build(&value).unwrap();
     let ir = CloudformationProgramIr::new_from_parse_tree(&cfn_tree).unwrap();
-    TypescriptSynthesizer::output(ir);
+    let output: String = TypescriptSynthesizer::output(ir);
+
+    if matches.is_present("OUTPUT") {
+        fs::write(matches.value_of("OUTPUT").unwrap(), output).expect("Unable to write file");
+    } else {
+        println!("{}", output);
+    }
 }

src/parser/lookup_table.rs

@@ -62,10 +62,10 @@ pub enum MappingInnerValue {
 impl Display for MappingInnerValue {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         return match self {
-            MappingInnerValue::String(string_val) => write!(f, "\"{}\"", string_val),
+            MappingInnerValue::String(string_val) => write!(f, "'{}'", string_val),
             MappingInnerValue::List(list_val) => {
                 let quoted_list_values: Vec<String> =
-                    list_val.iter().map(|val| format!("\"{}\"", val)).collect();
+                    list_val.iter().map(|val| format!("'{}'", val)).collect();
                 write!(f, "[{}]", quoted_list_values.join(","))
             }
         };
@@ -123,7 +123,7 @@ fn convert_to_string_vector(
                         "List values for mappings must be a string. Found {:?}, for key {}",
                         inner_key, vector_val
                     ),
-                })
+                });
             }
         };
         string_vector.push(converted_val);