fix(#196): fix prettier unspecified printWidth

issue introduced in #195.
was causing inline decorators to move to the line above because
`Number(undefined)` is 0, and having a printWidth of 0 breaks
all sorts of formatting.

lib/rules/decorator-position.js

@@ -317,7 +317,7 @@ function lineLength(userOptions, filePath) {
   const isEnabled = eslintPrettierRules[0] === 'error';
 
   if (!isEnabled) {
-    return {};
+    return { printWidth: Infinity };
   }
 
   const eslintPrettierOptions = eslintPrettierRules[1] || {};
@@ -332,13 +332,15 @@ function lineLength(userOptions, filePath) {
     filePath,
   });
 
-  console.log({
-    usePrettierrc,
-    eslintPrettierOptions,
-    eslintPrettierRules,
-    prettierOptions,
-    prettierRcOptions,
-  });
+  if (!('printWidth' in prettierOptions)) {
+    // 80 is prettier default
+    // eslint-disable-next-line no-console
+    console.warn(
+      'WARNING(eslint-plugin-decorator-position): printWidth not set in the prettier config, defaulting to 80'
+    );
+
+    return { ...prettierOptions, ...userOptions, printWidth: 80 };
+  }
 
   return Object.assign({}, prettierOptions, userOptions);
 }