Preserve newlines on copy + paste (#83)

* empty line input now yields newline instead of empty string

* Update unit tests to expect newline

* Update snapshots to expect newline

* ensure files have CRLF EoL - project convention

src/components/__tests__/__snapshots__/Highlight.test.js.snap

@@ -203,7 +203,10 @@ exports[`<Highlight /> snapshots renders correctly 1`] = `
       <span
         class="token plain"
         style="display: inline-block;"
-      />
+      >
+        
+
+      </span>
     </div>
     <div
       class="token-line"
@@ -339,7 +342,10 @@ exports[`<Highlight /> snapshots renders unsupported languages correctly 1`] = `
       <span
         class="token plain"
         style="display: inline-block;"
-      />
+      >
+        
+
+      </span>
     </div>
     <div
       class="token-line"

src/utils/__tests__/normalizeTokens.test.js

@@ -192,9 +192,9 @@ describe("normalizeTokens", () => {
     const output = normalizeTokens(input);
 
     expect(output).toEqual([
-      [{ types: ["plain"], content: "", empty: true }],
-      [{ types: ["plain"], content: "", empty: true }],
-      [{ types: ["plain"], content: "", empty: true }]
+      [{ types: ["plain"], content: "\n", empty: true }],
+      [{ types: ["plain"], content: "\n", empty: true }],
+      [{ types: ["plain"], content: "\n", empty: true }]
     ]);
   });
 });

src/utils/normalizeTokens.js

@@ -9,19 +9,17 @@ const normalizeEmptyLines = (line: Token[]) => {
   if (line.length === 0) {
     line.push({
       types: ["plain"],
-      content: "",
+      content: "\n",
       empty: true
     });
   } else if (line.length === 1 && line[0].content === "") {
+    line[0].content = "\n";
     line[0].empty = true;
   }
 };
 
-const appendTypes = (
-  types: string[],
-  add: string[] | string
-): string[] => {
-  const typesSize = types.length
+const appendTypes = (types: string[], add: string[] | string): string[] => {
+  const typesSize = types.length;
   if (typesSize > 0 && types[typesSize - 1] === add) {
     return types;
   }