[Python][R] Escape single quotes in strings (#2808) (#2809)

Author: fsonntag

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonClientCodegen.java

@@ -634,7 +634,7 @@ public String toDefaultValue(Schema p) {
                 if (Pattern.compile("\r\n|\r|\n").matcher((String) p.getDefault()).find())
                     return "'''" + p.getDefault() + "'''";
                 else
-                    return "'" + p.getDefault() + "'";
+                    return "'" + ((String) p.getDefault()).replaceAll("'","\'") + "'";
             }
         } else if (ModelUtils.isArraySchema(p)) {
             if (p.getDefault() != null) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RClientCodegen.java

@@ -569,7 +569,7 @@ public String toDefaultValue(Schema p) {
                 if (Pattern.compile("\r\n|\r|\n").matcher((String) p.getDefault()).find())
                     return "'''" + p.getDefault() + "'''";
                 else
-                    return "'" + p.getDefault() + "'";
+                    return "'" + ((String) p.getDefault()).replaceAll("'","\'") + "'";
             }
         } else if (ModelUtils.isArraySchema(p)) {
             if (p.getDefault() != null) {

modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonClientCodegenTest.java

@@ -92,4 +92,13 @@ public void testRegularExpressionOpenAPISchemaVersion3() {
         // pattern_with_modifiers '/^pattern\d{3}$/i
         Assert.assertEquals(op.allParams.get(5).pattern, "/^pattern\\d{3}$/i");
     }
+
+    @Test(description = "test single quotes escape")
+    public void testSingleQuotes() {
+        final PythonClientCodegen codegen = new PythonClientCodegen();
+        StringSchema schema = new StringSchema();
+        schema.setDefault("Text containing 'single' quote");
+        String defaultValue = codegen.toDefaultValue(schema);
+        Assert.assertEquals("'Text containing \'single\' quote'", defaultValue);
+    }
 }