Make the analyze-field-access command exit with 1 on error

Refs: #20

scripts/analyze-field-access.ts

@@ -10,6 +10,8 @@ const options = {
   target: ts.ScriptTarget.ES2015,
   module: ts.ModuleKind.CommonJS,
 };
+// We'll be populating this when we detect unused fields
+const errors: string[] = [];
 
 let program = ts.createProgram(fileNames, options);
 let checker = program.getTypeChecker();
@@ -22,6 +24,12 @@ for (const sourceFile of program.getSourceFiles()) {
   }
 }
 
+if (errors.length > 0) {
+  console.log(`Found ${errors.length} problems:\n`);
+  console.error(errors.join("\n\n"));
+  process.exit(1);
+}
+
 function isSyntaxMapFile(fileName: string): boolean {
   return (
     fileName.includes("src/syntax/") && !fileName.endsWith("transformMap.ts")
@@ -74,12 +82,13 @@ function analyzeObjectProperty(node: ts.Node, sourceFile: ts.SourceFile) {
     .map(([key]) => key);
 
   if (missingFields.length > 0) {
-    console.log(``);
-    console.log(`Unused fields: ${missingFields.join(", ")}`);
-    console.log(
-      `In file: ${sourceFile.fileName.replace(/.*\//, "src/syntax/")}`,
+    errors.push(
+      [
+        `In file: ${sourceFile.fileName.replace(/.*\//, "src/syntax/")}`,
+        `Unused fields: ${missingFields.join(", ")}`,
+        node.getText(sourceFile),
+      ].join("\n"),
     );
-    console.log(node.getText(sourceFile));
   }
 }