Normalize paths for cap

This fixes #788.

CHANGELOG.md

@@ -6,6 +6,8 @@ All notable changes to this project will be documented in this file.
 
 - Allow overriding env using tags, fixes [#792](https://github.com/badeball/cypress-cucumber-preprocessor/issues/792).
 
+- Correct some path handling on Windows, fixes [#788](https://github.com/badeball/cypress-cucumber-preprocessor/issues/788).
+
 ## v12.0.0
 
 Breaking changes:

features/issues/788.feature

@@ -0,0 +1,29 @@
+# https://github.com/badeball/cypress-cucumber-preprocessor/issues/788
+
+Feature: calculating common ancestor path
+  Scenario:
+    Given a file named "cypress/e2e/1/a.feature" with:
+      """
+      Feature: a feature
+        Scenario: a scenario
+          Given a step
+      """
+    And a file named "cypress/e2e/2/a.feature" with:
+      """
+      Feature: a feature
+        Scenario: a scenario
+          Given a step
+      """
+    And a file named "cypress/e2e/3/a.feature" with:
+      """
+      Feature: a feature
+        Scenario: a scenario
+          Given a step
+      """
+    And a file named "cypress/support/step_definitions/steps.js" with:
+      """
+      const { Given } = require("@badeball/cypress-cucumber-preprocessor");
+      Given("a step", function() {})
+      """
+    When I run cypress
+    Then it passes

lib/template.ts

@@ -65,7 +65,9 @@ export async function compile(
   const pickles = envelopes.map((envelope) => envelope.pickle).filter(notNull);
 
   const implicitIntegrationFolder = assertAndReturn(
-    ancestor(...getTestFiles(configuration).map(path.dirname)),
+    ancestor(
+      ...getTestFiles(configuration).map(path.dirname).map(path.normalize)
+    ),
     "Expected to find a common ancestor path"
   );