refactor: have the precompile function take in the full application code and always be called from compileApplicationToWasm

This makes it simpler to test the regex precompilation functionality and makes it simpler to add more precompilation phases in the future

Author: Jake Champion

src/compileApplicationToWasm.js

@@ -31,14 +31,22 @@ const PREAMBLE = `;{
   const precompile = (r) => { r.exec('a'); r.exec('\\u1000'); };`;
 const POSTAMBLE = "}";
 
+// TODO: This should also detect and update sourcemaps if they are present, otherwise the sourcemaps would be incorrect.
+// 
 /// Emit a block of javascript that will pre-compile the regular expressions given. As spidermonkey
 /// will intern regular expressions, duplicating them at the top level and testing them with both
 /// an ascii and utf8 string should ensure that they won't be re-compiled when run in the fetch
 /// handler.
-function precompile(literals) {
+function precompile(inputApplication) {
+  let lits = findRegexLiterals(inputApplication);
+
+  if (lits.length === 0) {
+    return inputApplication;
+  }
+
   return (
     PREAMBLE +
-    literals
+    lits
       .map((regex) => {
         return `precompile(/${regex.pattern}/${regex.flags});`;
       })
@@ -113,11 +121,7 @@ export async function compileApplicationToWasm(input, output, wasmEngine) {
     process.exit(1);
   }
 
-  let lits = findRegexLiterals(inputContents);
-
-  if (lits.length != 0) {
-    inputContents += precompile(lits);
-  }
+  let application = precompile(inputContents);
 
   try {
     let wizerProcess = spawnSync(
@@ -131,7 +135,7 @@ export async function compileApplicationToWasm(input, output, wasmEngine) {
       ],
       {
         stdio: [null, process.stdout, process.stderr],
-        input: inputContents,
+        input: application,
         shell: true,
         encoding: "utf-8",
       }