From b28421f3f41ed7c888c0cb133a35fc0ddb887f70 Mon Sep 17 00:00:00 2001
From: Doug <douglas_b_gray@yahoo.cm>
Date: Sun, 15 Nov 2020 18:22:50 -0800
Subject: [PATCH] Issue 8412: Replace vars with defaults in server evaluation.

---
 .../swagger/codegen/v3/utils/URLPathUtil.java | 22 ++++++++++--
 .../codegen/v3/utils/URLPathUtilTest.java     | 34 +++++++++++++++++++
 2 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/v3/utils/URLPathUtil.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/v3/utils/URLPathUtil.java
index 95ab319e28c..ee4149bde1a 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/v3/utils/URLPathUtil.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/v3/utils/URLPathUtil.java
@@ -3,13 +3,17 @@
 import io.swagger.codegen.v3.CodegenConfig;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.servers.Server;
+import io.swagger.v3.oas.models.servers.ServerVariables;
 import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.text.StrSubstitutor;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
 
 public class URLPathUtil {
 
@@ -30,7 +34,8 @@ public static URL getServerURL(OpenAPI openAPI) {
             url = LOCAL_HOST + url;
         }
         try {
-            return new URL(url);
+            String varReplacedUrl = replaceServerVarsWthDefaultValues(url, server.getVariables());
+            return new URL(varReplacedUrl);
         } catch (MalformedURLException e) {
             LOGGER.warn("Not valid URL: " + server.getUrl(), e);
             return null;
@@ -67,7 +72,8 @@ public static URL getServerURL(OpenAPI openAPI, CodegenConfig config) {
                 serverUrl = inputURL;
                 break;
             }
-            return new URL(serverUrl);
+            String varReplacedUrl = replaceServerVarsWthDefaultValues(serverUrl, server.getVariables());
+            return new URL(varReplacedUrl);
         } catch (Exception e) {
             LOGGER.warn("Not valid URL: " + server.getUrl(), e);
             return null;
@@ -94,4 +100,16 @@ public static String getHost(OpenAPI openAPI){
         }
         return LOCAL_HOST;
     }
+
+    private static String replaceServerVarsWthDefaultValues(String url, ServerVariables vars) {
+        if (vars != null && vars.size() > 0) {
+            Map<String, Object> defaultValues = vars.entrySet()
+                .stream()
+                .collect(Collectors.toMap(
+                    Map.Entry::getKey,
+                    e -> e.getValue().getDefault()));
+            return StrSubstitutor.replace(url, defaultValues, "{", "}");
+        }
+        return url;
+    }
 }
diff --git a/modules/swagger-codegen/src/test/java/io/swagger/codegen/v3/utils/URLPathUtilTest.java b/modules/swagger-codegen/src/test/java/io/swagger/codegen/v3/utils/URLPathUtilTest.java
index 822801eaa40..21b72363228 100644
--- a/modules/swagger-codegen/src/test/java/io/swagger/codegen/v3/utils/URLPathUtilTest.java
+++ b/modules/swagger-codegen/src/test/java/io/swagger/codegen/v3/utils/URLPathUtilTest.java
@@ -3,6 +3,8 @@
 import io.swagger.codegen.v3.CodegenConfig;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.servers.Server;
+import io.swagger.v3.oas.models.servers.ServerVariable;
+import io.swagger.v3.oas.models.servers.ServerVariables;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 import org.testng.Assert;
@@ -118,4 +120,36 @@ public void testRelativeServerURLv3() {
         verify(servers).isEmpty();
         verify(config).getInputURL();
     }
+
+    @Test (description = "verify a url with variable substitutions.")
+    public void testVariableSubstitution() throws Exception {
+        ServerVariable portVariable = new ServerVariable();
+        portVariable.setDefault("8080");
+
+        ServerVariables vars = new ServerVariables();
+        vars.addServerVariable("port", portVariable);
+
+        when(server.getVariables()).thenReturn(vars);
+        when(server.getUrl()).thenReturn("http://myhost:{port}/mypath");
+
+        URL url = URLPathUtil.getServerURL(openAPI, config);
+
+        Assert.assertEquals(new URL("http://myhost:8080/mypath"), url);
+    }
+
+    @Test (description = "verify a url with variable substitutions when default is missing.")
+    public void testVariableSubstitutionMissingDefault() throws Exception {
+        ServerVariable portVariable = new ServerVariable();
+
+        ServerVariables vars = new ServerVariables();
+        vars.addServerVariable("port", portVariable);
+
+        when(server.getVariables()).thenReturn(vars);
+        when(server.getUrl()).thenReturn("http://myhost:{port}/mypath");
+
+        // No default for port, resulting URL is invalid.
+        URL url = URLPathUtil.getServerURL(openAPI, config);
+
+        Assert.assertNull(url);
+    }
 }