Corrected remote document lookup behavior

When remote documents are requested and there is no way to know the base URL, the index will now try and determine the base path from the way the spec was loaded (if it comes in remote, we use the base URL of the spec)

document_test.go

@@ -504,6 +504,35 @@ paths:
 
 	assert.Equal(t, d, strings.TrimSpace(string(rend)))
 }
+
+func TestDocument_RemoteWithoutBaseURL(t *testing.T) {
+
+	// This test will push the index to do try and locate remote references that use relative references
+	spec := `openapi: 3.0.2
+info:
+  title: Test
+  version: 1.0.0
+paths:
+  /test:
+    get:
+      parameters:
+        - $ref: "https://schemas.opengis.net/ogcapi/features/part2/1.0/openapi/ogcapi-features-2.yaml#/components/parameters/crs"`
+
+	config := datamodel.NewOpenDocumentConfiguration()
+
+	doc, err := NewDocumentWithConfiguration([]byte(spec), config)
+	if err != nil {
+		panic(err)
+	}
+
+	result, errs := doc.BuildV3Model()
+	if len(errs) > 0 {
+		panic(errs)
+	}
+
+	assert.Equal(t, "crs", result.Model.Paths.PathItems["/test"].Get.Parameters[0].Name)
+}
+
 func TestDocument_ExampleMap(t *testing.T) {
 	var d = `openapi: "3.1"
 components:

index/find_component.go

@@ -325,8 +325,18 @@ func (index *SpecIndex) performExternalLookup(uri []string, componentId string,
 				newBasePath = filepath.Dir(filepath.Join(index.config.BasePath, filepath.Dir(newUrl.Path)))
 			}
 			if bd != "" {
+				if len(uri[0]) > 0 {
+					// if there is no base url defined, but we can know we have been requested remotely,
+					// set the base url to the remote url base path.
+					if newUrl == nil || newUrl.String() != uri[0] {
+						ur, _ := url.Parse(uri[0])
+						newUrl, _ = url.Parse(fmt.Sprintf("%s://%s%s", ur.Scheme, ur.Host, filepath.Dir(ur.Path)))
+					}
+					newBasePath = filepath.Dir(filepath.Join(bd, uri[1]))
+				} else {
 					newBasePath = filepath.Dir(filepath.Join(bd, uri[0]))
 				}
+			}
 
 			if newUrl != nil || newBasePath != "" {
 				newConfig := &SpecIndexConfig{

index/find_component_test.go

@@ -99,3 +99,30 @@ components:
 	assert.Nil(t, thing)
 	assert.Len(t, index.GetReferenceIndexErrors(), 1)
 }
+
+func TestSpecIndex_LocateRemoteDocsWithNoBaseURLSupplied(t *testing.T) {
+	// This test will push the index to do try and locate remote references that use relative references
+	spec := `openapi: 3.0.2
+info:
+  title: Test
+  version: 1.0.0
+paths:
+  /test:
+    get:
+      parameters:
+        - $ref: "https://schemas.opengis.net/ogcapi/features/part2/1.0/openapi/ogcapi-features-2.yaml#/components/parameters/crs"`
+
+	var rootNode yaml.Node
+	_ = yaml.Unmarshal([]byte(spec), &rootNode)
+
+	c := CreateOpenAPIIndexConfig()
+	index := NewSpecIndexWithConfig(&rootNode, c)
+
+	// extract crs param from index
+	crsParam := index.GetMappedReferences()["https://schemas.opengis.net/ogcapi/features/part2/1.0/openapi/ogcapi-features-2.yaml#/components/parameters/crs"]
+	assert.NotNil(t, crsParam)
+	assert.True(t, crsParam.IsRemote)
+	assert.Equal(t, "crs", crsParam.Node.Content[1].Value)
+	assert.Equal(t, "query", crsParam.Node.Content[3].Value)
+	assert.Equal(t, "form", crsParam.Node.Content[9].Value)
+}