Fixes regex pattern handling

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

@@ -1041,7 +1041,9 @@ public CodegenProperty fromProperty(String name, Schema p, boolean required, boo
             cp.isNullable = false;
             cp.setHasMultipleTypes(true);
         }
-        postProcessPattern(cp.pattern, cp.vendorExtensions);
+        if (p.getPattern() != null) {
+            postProcessPattern(p.getPattern(), cp.vendorExtensions);
+        }
         // if we have a property that has a difficult name, either:
         // 1. name is reserved, like class int float
         // 2. name is invalid in python like '3rd' or 'Content-Type'
@@ -1485,7 +1487,11 @@ protected Object processTestExampleData(Object value) {
     @Override
     public CodegenModel fromModel(String name, Schema sc) {
         CodegenModel cm = super.fromModel(name, sc);
-
+        if (sc.getPattern() != null) {
+            postProcessPattern(sc.getPattern(), cm.vendorExtensions);
+            String pattern = (String) cm.vendorExtensions.get("x-regex");
+            cm.setPattern(pattern);
+        }
         if (cm.isNullable) {
             cm.setIsNull(true);
             cm.isNullable = false;
@@ -1891,34 +1897,21 @@ private String toExampleValueRecursive(String modelName, Schema schema, Object o
                 example = "2";
             } else if (StringUtils.isNotBlank(schema.getPattern())) {
                 String pattern = schema.getPattern();
+                List<Object> results = getPatternAndModifiers(pattern);
+                String extractedPattern = (String) results.get(0);
+                List<String> regexFlags = (List<String>) results.get(1);
                 /*
                 RxGen does not support our ECMA dialect https://github.com/curious-odd-man/RgxGen/issues/56
                 So strip off the leading / and trailing / and turn on ignore case if we have it
                  */
-                Pattern valueExtractor = Pattern.compile("^/?(.+?)/?(.?)$");
-                Matcher m = valueExtractor.matcher(pattern);
                 RgxGen rgxGen = null;
-                if (m.find()) {
-                    int groupCount = m.groupCount();
-                    if (groupCount == 1) {
-                        // only pattern found
-                        String isolatedPattern = m.group(1);
-                        rgxGen = new RgxGen(isolatedPattern);
-                    } else if (groupCount == 2) {
-                        // patterns and flag found
-                        String isolatedPattern = m.group(1);
-                        String flags = m.group(2);
-                        if (flags.contains("i")) {
-                            rgxGen = new RgxGen(isolatedPattern);
-                            RgxGenProperties properties = new RgxGenProperties();
-                            RgxGenOption.CASE_INSENSITIVE.setInProperties(properties, true);
-                            rgxGen.setProperties(properties);
-                        } else {
-                            rgxGen = new RgxGen(isolatedPattern);
-                        }
-                    }
+                if (regexFlags.size() > 0 && regexFlags.contains("i")) {
+                    rgxGen = new RgxGen(extractedPattern);
+                    RgxGenProperties properties = new RgxGenProperties();
+                    RgxGenOption.CASE_INSENSITIVE.setInProperties(properties, true);
+                    rgxGen.setProperties(properties);
                 } else {
-                    rgxGen = new RgxGen(pattern);
+                    rgxGen = new RgxGen(extractedPattern);
                 }
 
                 // this seed makes it so if we have [a-z] we pick a
@@ -2358,6 +2351,16 @@ protected void updatePropertyForString(CodegenProperty property, Schema p) {
         property.pattern = toRegularExpression(p.getPattern());
     }
 
+    @Override
+    public String toRegularExpression(String pattern) {
+        if (pattern == null) {
+            return null;
+        }
+        List<Object> results = getPatternAndModifiers(pattern);
+        String extractedPattern = (String) results.get(0);
+        return extractedPattern;
+    }
+
     protected void updatePropertyForNumber(CodegenProperty property, Schema p) {
         property.setIsNumber(true);
         // float and double differentiation is determined with format info
@@ -2482,35 +2485,61 @@ public ModelsMap postProcessModels(ModelsMap objs) {
         return postProcessModelsEnum(objs);
     }
 
+    /**
+     * @param pattern the regex pattern
+     * @return List<String pattern, List<String modifer>>
+     */
+    private List<Object> getPatternAndModifiers(String pattern) {
+        /*
+        Notes:
+        RxGen does not support our ECMA dialect https://github.com/curious-odd-man/RgxGen/issues/56
+        So strip off the leading / and trailing / and turn on ignore case if we have it
+
+        json schema test cases omit the leading and trailing /s, so make sure that the regex allows that
+         */
+        Pattern valueExtractor = Pattern.compile("^/?(.+?)/?([simu]{0,4})$");
+        Matcher m = valueExtractor.matcher(pattern);
+        if (m.find()) {
+            int groupCount = m.groupCount();
+            if (groupCount == 1) {
+                // only pattern found
+                String isolatedPattern = m.group(1);
+                return Arrays.asList(isolatedPattern, null);
+            } else if (groupCount == 2) {
+                List<String> modifiers = new ArrayList<String>();
+                // patterns and flag found
+                String isolatedPattern = m.group(1);
+                String flags = m.group(2);
+                if (flags.contains("s")) {
+                    modifiers.add("DOTALL");
+                }
+                if (flags.contains("i")) {
+                    modifiers.add("IGNORECASE");
+                }
+                if (flags.contains("m")) {
+                    modifiers.add("MULTILINE");
+                }
+                return Arrays.asList(isolatedPattern, modifiers);
+            }
+        }
+        return Arrays.asList(pattern, new ArrayList<String>());
+    }
+
     /*
      * The OpenAPI pattern spec follows the Perl convention and style of modifiers. Python
      * does not support this in as natural a way so it needs to convert it. See
      * https://docs.python.org/2/howto/regex.html#compilation-flags for details.
      */
     public void postProcessPattern(String pattern, Map<String, Object> vendorExtensions) {
         if (pattern != null) {
-            int regexLength = pattern.length();
-            String regex = pattern;
-            int i = pattern.lastIndexOf('/');
-            if (regexLength >= 2 && pattern.charAt(0) == '/' && i != -1) {
-                // json schema tests do not include the leading and trailing slashes
-                // so I do not think that they are required
-                regex = pattern.substring(1, i);
-            }
-            regex = regex.replace("'", "\\'");
-            List<String> modifiers = new ArrayList<String>();
-
-            if (i != -1) {
-                for (char c : pattern.substring(i).toCharArray()) {
-                    if (regexModifiers.containsKey(c)) {
-                        String modifier = regexModifiers.get(c);
-                        modifiers.add(modifier);
-                    }
-                }
-            }
+            List<Object> results = getPatternAndModifiers(pattern);
+            String extractedPattern = (String) results.get(0);
+            List<String> modifiers = (List<String>) results.get(1);
 
-            vendorExtensions.put("x-regex", regex);
-            vendorExtensions.put("x-modifiers", modifiers);
+            vendorExtensions.put("x-regex", extractedPattern);
+            if (modifiers.size() > 0) {
+                vendorExtensions.put("x-modifiers", modifiers);
+            }
         }
     }
 

modules/openapi-json-schema-generator/src/test/java/org/openapitools/codegen/python/PythonClientTest.java

@@ -32,6 +32,7 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -164,4 +165,36 @@ public void testApisNotGenerated() throws Exception {
         Assert.assertFalse(Files.isDirectory(pathThatShouldNotExist));
         output.deleteOnExit();
     }
+
+    @Test
+    public void testRegexWithoutTrailingSlashWorks() {
+        OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/11_regex.yaml");
+        PythonClientCodegen codegen = new PythonClientCodegen();
+        codegen.setOpenAPI(openAPI);
+
+        String modelName = "UUID";
+        Schema schema = openAPI.getComponents().getSchemas().get(modelName);
+
+        CodegenModel cm = codegen.fromModel(modelName, schema);
+        String expectedRegexPattern = "[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}";
+        Assert.assertEquals(cm.getPattern(), expectedRegexPattern);
+        Assert.assertEquals(cm.vendorExtensions.get("x-regex"), expectedRegexPattern);
+        Assert.assertFalse(cm.vendorExtensions.containsKey("x-modifiers"));
+    }
+
+    @Test
+    public void testRegexWithMultipleFlagsWorks() {
+        OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/11_regex.yaml");
+        PythonClientCodegen codegen = new PythonClientCodegen();
+        codegen.setOpenAPI(openAPI);
+
+        String modelName = "StringWithRegexWithThreeFlags";
+        Schema schema = openAPI.getComponents().getSchemas().get(modelName);
+
+        CodegenModel cm = codegen.fromModel(modelName, schema);
+        String expectedRegexPattern = "a.";
+        Assert.assertEquals(cm.getPattern(), expectedRegexPattern);
+        Assert.assertEquals(cm.vendorExtensions.get("x-regex"), expectedRegexPattern);
+        Assert.assertEquals(cm.vendorExtensions.get("x-modifiers"), Arrays.asList("DOTALL", "IGNORECASE", "MULTILINE"));
+    }
 }

modules/openapi-json-schema-generator/src/test/resources/3_0/11_regex.yaml

@@ -0,0 +1,27 @@
+openapi: 3.0.3
+info:
+  title: Test
+  version: 1.0.0-SNAPSHOT
+paths:
+  /test:
+    get:
+      tags:
+        - Test Resource
+      parameters:
+        - name: uuid
+          in: query
+          schema:
+            $ref: '#/components/schemas/UUID'
+      responses:
+        "200":
+          description: OK
+components:
+  schemas:
+    UUID:
+      format: uuid
+      pattern: "[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}"
+      type: string
+    StringWithRegexWithThreeFlags:
+      format: uuid
+      pattern: "/a./sim"
+      type: string

samples/openapi3/client/petstore/python/docs/apis/tags/FakeApi.md

@@ -949,8 +949,8 @@ with petstore_api.ApiClient(configuration) as api_client:
         number=32.1,
         _float=3.14,
         double=67.8,
-        string="A",
-        pattern_without_delimiter="Aj",
+        string="a",
+        pattern_without_delimiter="AUR,rZ#UM/?R,Fp^l6$ARjbhJk C>",
         byte='YQ==',
         binary=open('/path/to/file', 'rb'),
         date="1970-01-01",