Export visit utility function as visit.js

This is likely to be useful to classes which extend
OpenApiTransformerBase.

Signed-off-by: Kevin Locke <[email protected]>

Author: kevinoid

index.js

@@ -6,8 +6,8 @@
 
 'use strict';
 
-const assert = require('assert');
 const { METHODS } = require('http');
+const visit = require('./visit.js');
 
 const { isArray } = Array;
 
@@ -18,44 +18,6 @@ const { isArray } = Array;
  */
 const httpMethodSet = new Set(METHODS);
 
-/** Visits a property by adding its name to transformPath while calling a
- * given method with a given value.
- *
- * @private
- * @template ArgsType, TransformedType
- * @param {!OpenApiTransformerBase} transformer Transformer on which
- * transformPath will be modified.
- * @param {function(this:!OpenApiTransformerBase, ...ArgsType):
- * TransformedType} method Method to be called.
- * @param {string} propName Name of property being visited.
- * @param {ArgsType} args Argument to method (usually property value).
- * @returns {TransformedType} Result of calling method on args.
- */
-function visit(transformer, method, propName, ...args) {
-  transformer.transformPath.push(propName);
-
-  let handlingException = false;
-  try {
-    return method.apply(transformer, args);
-  } catch (err) {
-    handlingException = true;
-    if (err instanceof Error && !hasOwnProperty.call(err, 'transformPath')) {
-      err.transformPath = [...transformer.transformPath];
-      err.message +=
-        ` (while transforming /${err.transformPath.join('/')})`;
-    }
-
-    throw err;
-  } finally {
-    const popProp = transformer.transformPath.pop();
-
-    // Avoid clobbering an exception which is already propagating
-    if (!handlingException) {
-      assert.strictEqual(popProp, propName);
-    }
-  }
-}
-
 /** Transforms a value which has type object<string,ValueType> but is not
  * defined as Map[string,ValueType] in OpenAPI.
  *

package.json

@@ -27,7 +27,8 @@
   "main": "index.js",
   "exports": {
     ".": "./index.js",
-    "./package.json": "./package.json"
+    "./package.json": "./package.json",
+    "./visit.js": "./visit.js"
   },
   "//": "All scripts should run in POSIX sh and Windows cmd.exe",
   "scripts": {

visit.js

@@ -0,0 +1,47 @@
+/**
+ * @copyright Copyright 2021 Kevin Locke <[email protected]>
+ * @license MIT
+ * @module "openapi-transformer-base/visit.js"
+ */
+
+'use strict';
+
+const assert = require('assert');
+
+/** Visits a property being transformed by an OpenApiTransformerBase by adding
+ * its name to transformPath while calling a given method with a given value.
+ *
+ * @template ArgsType, TransformedType
+ * @param {!module:openapi-transformer-base} transformer Transformer on which
+ * transformPath will be modified.
+ * @param {function(this:!module:openapi-transformer-base, ...ArgsType):
+ * TransformedType} method Method to be called.
+ * @param {string} propName Name of property being visited.
+ * @param {ArgsType} args Argument to method (usually property value).
+ * @returns {TransformedType} Result of calling method on args.
+ */
+module.exports =
+function visit(transformer, method, propName, ...args) {
+  transformer.transformPath.push(propName);
+
+  let handlingException = false;
+  try {
+    return method.apply(transformer, args);
+  } catch (err) {
+    handlingException = true;
+    if (err instanceof Error && !hasOwnProperty.call(err, 'transformPath')) {
+      err.transformPath = [...transformer.transformPath];
+      err.message +=
+        ` (while transforming /${err.transformPath.join('/')})`;
+    }
+
+    throw err;
+  } finally {
+    const popProp = transformer.transformPath.pop();
+
+    // Avoid clobbering an exception which is already propagating
+    if (!handlingException) {
+      assert.strictEqual(popProp, propName);
+    }
+  }
+};