fix: Fix .matchHeader() with allowUnmocked

lib/interceptor.js

@@ -165,6 +165,31 @@ Interceptor.prototype.replyWithFile = function replyWithFile(
   return this.reply(statusCode, readStream, headers)
 }
 
+/**
+ * Test to see if the headers match a filter. If the function cannot determin where the headers are
+ * it returns false.
+ * @name filterMatches
+ * @param {Object} filter - A filter object containing the header name we want to filter on and the
+ *                          filter value which can be a string, regex, or predicate.
+ * @param {Object} obj - An object containing the headers we wish to check. This is either the
+ *                       request options or the outgoing request.
+ * @returns {boolean} True if the headers contain a value that matches the filter.
+ */
+function filterMatches(filter, obj) {
+  let headerValue
+  if (obj.getHeader) {
+    headerValue = obj.getHeader(filter.name)
+  } else if (obj.headers) {
+    headerValue = obj.headers[filter.name]
+  } else {
+    return false
+  }
+  if (_.isFunction(filter.value)) {
+    return filter.value(headerValue)
+  }
+  return common.matchStringOrRegexp(headerValue, filter.value)
+}
+
 // Also match request headers
 // https://github.com/pgte/nock/issues/163
 Interceptor.prototype.reqheaderMatches = function reqheaderMatches(
@@ -227,14 +252,8 @@ Interceptor.prototype.match = function match(options, body, hostNameOnly) {
     body = this.scope.transformRequestBodyFunction(body, this._requestBody)
   }
 
-  const checkHeaders = function(header) {
-    if (_.isFunction(header.value)) {
-      return header.value(options.getHeader(header.name))
-    }
-    return common.matchStringOrRegexp(
-      options.getHeader(header.name),
-      header.value
-    )
+  const checkHeaders = function(filter) {
+    return filterMatches(filter, options)
   }
 
   if (
@@ -393,12 +412,8 @@ Interceptor.prototype.matchIndependentOfBody = function matchIndependentOfBody(
   if (this.scope.transformPathFunction) {
     path = this.scope.transformPathFunction(path)
   }
-
-  const checkHeaders = function(header) {
-    return (
-      options.getHeader &&
-      common.matchStringOrRegexp(options.getHeader(header.name), header.value)
-    )
+  const checkHeaders = function(filter) {
+    return filterMatches(filter, options)
   }
 
   if (

tests/test_header_matching.js

@@ -82,7 +82,7 @@ test('match headers on number with regexp', async t => {
 })
 
 test('match header on scope with function: gets the expected argument', async t => {
-  t.plan(3)
+  t.plan(4) // The check in matchHeader should run twice
 
   const scope = nock('http://example.test')
     .get('/')
@@ -118,6 +118,21 @@ test('match header on scope with function: matches when match accepted', async t
   scope.done()
 })
 
+test('match header on scope with function and allow unmocked: matches when match accepted', async t => {
+  const scope = nock('http://example.test', { allowUnmocked: true })
+    .get('/')
+    .matchHeader('x-my-headers', val => true)
+    .reply(200, 'Hello World!')
+
+  const { statusCode, body } = await got('http://example.test/', {
+    headers: { 'X-My-Headers': 456 },
+  })
+
+  t.equal(statusCode, 200)
+  t.equal(body, 'Hello World!')
+  scope.done()
+})
+
 test('match header on scope with function: does not match when match declined', async t => {
   nock('http://example.test')
     .get('/')
@@ -152,7 +167,7 @@ test('match header on scope with function: does not consume mock request when ma
 })
 
 test('match header on intercept with function: gets the expected argument', async t => {
-  t.plan(3)
+  t.plan(4) // The check in matchHeader should run twice
 
   const scope = nock('http://example.test')
     .matchHeader('x-my-headers', val => {
@@ -192,6 +207,23 @@ test('match header on interceptor with function: matches when match accepted', a
   scope.done()
 })
 
+test('match header on interceptor with function: matches when match accepted', async t => {
+  const scope = nock('http://example.test', { allowUnmocked: true })
+    .matchHeader('x-my-headers', val => true)
+    // `.matchHeader()` is called on the interceptor. It precedes the call to
+    // `.get()`.
+    .get('/')
+    .reply(200, 'Hello World!')
+
+  const { statusCode, body } = await got('http://example.test/', {
+    headers: { 'X-My-Headers': 456 },
+  })
+
+  t.equal(statusCode, 200)
+  t.equal(body, 'Hello World!')
+  scope.done()
+})
+
 test('match header on interceptor with function: does not match when match declined', async t => {
   nock('http://example.test')
     .matchHeader('x-my-headers', val => false)