fix: treat example values starting with numbers as strings

Author: daniel-kmiecik

modules/swagger-core/src/main/java/io/swagger/v3/core/util/AnnotationsUtils.java

@@ -765,15 +765,7 @@ public static Optional<Schema> getSchemaFromAnnotation(
             schemaObject.setDefault(schema.defaultValue());
         }
         if (StringUtils.isNotBlank(schema.example())) {
-            try {
-                if (openapi31) {
-                    schemaObject.setExample(Json31.mapper().readTree(schema.example()));
-                } else {
-                    schemaObject.setExample(Json.mapper().readTree(schema.example()));
-                }
-            } catch (IOException e) {
-                schemaObject.setExample(schema.example());
-            }
+            setExampleSchema(schema, openapi31, schemaObject);
         }
         if (StringUtils.isNotBlank(schema.format())) {
             schemaObject.setFormat(schema.format());
@@ -892,6 +884,25 @@ public static Optional<Schema> getSchemaFromAnnotation(
         return Optional.of(schemaObject);
     }
 
+    private static void setExampleSchema(io.swagger.v3.oas.annotations.media.Schema schema, boolean openapi31, Schema schemaObject) {
+        String exampleValue = schema.example().trim();
+
+        // Prevent numeric-starting example strings (e.g. "5 lacs per annum") from being parsed as numbers
+        if (exampleValue.matches("^\\d.*") && !exampleValue.startsWith("\"")) {
+            schemaObject.setExample(exampleValue);
+        } else {
+            try {
+                if (openapi31) {
+                    schemaObject.setExample(Json31.mapper().readTree(exampleValue));
+                } else {
+                    schemaObject.setExample(Json.mapper().readTree(exampleValue));
+                }
+            } catch (IOException e) {
+                schemaObject.setExample(exampleValue);
+            }
+        }
+    }
+
     public static Schema resolveSchemaFromType(Class<?> schemaImplementation, Components components, JsonView jsonViewAnnotation) {
         return resolveSchemaFromType(schemaImplementation, components, jsonViewAnnotation, false);
     }

modules/swagger-core/src/test/java/io/swagger/v3/core/util/AnnotationsUtilsTest.java

@@ -54,9 +54,9 @@ private Object[][] expectedSchemaFromTypes() {
     public void resolveSchemaFromType(Class<?> aClass, Map<String, Object> expected) {
         Schema schema = AnnotationsUtils.resolveSchemaFromType(aClass, new Components(), null);
 
-       assertEquals(schema.getType(), expected.get("type"));
-       assertEquals(schema.getFormat(), expected.get("format"));
-       assertEquals(schema.get$ref(), expected.get("$ref"));
+        assertEquals(schema.getType(), expected.get("type"));
+        assertEquals(schema.getFormat(), expected.get("format"));
+        assertEquals(schema.get$ref(), expected.get("$ref"));
     }
 
     @DataProvider
@@ -75,10 +75,10 @@ public void getSchema(String methodName, Map<String, Object> expected) throws No
         Content annotationContent = method.getAnnotation(ApiResponse.class).content()[0];
         Optional<? extends Schema> schema = AnnotationsUtils.getSchema(annotationContent, new Components(), null, false);
 
-       assertTrue(schema.isPresent());
-       assertEquals(schema.get().getType(), expected.get("type"));
-       assertEquals(schema.get().getFormat(), expected.get("format"));
-       assertEquals(schema.get().get$ref(), expected.get("$ref"));
+        assertTrue(schema.isPresent());
+        assertEquals(schema.get().getType(), expected.get("type"));
+        assertEquals(schema.get().getFormat(), expected.get("format"));
+        assertEquals(schema.get().get$ref(), expected.get("$ref"));
     }
 
     @ApiResponse(content = @Content(schema = @io.swagger.v3.oas.annotations.media.Schema(implementation = Byte.class)))
@@ -99,4 +99,31 @@ private void dummyType() {
 
     class DummyClass implements Serializable {}
 
+    static class ExampleHolder {
+        @io.swagger.v3.oas.annotations.media.Schema(type = "string", example = "5 lacs per annum")
+        String value;
+    }
+
+    @Test
+    public void testExampleStartingWithNumberShouldBeString() throws Exception {
+        io.swagger.v3.oas.annotations.media.Schema schemaAnnotation =
+                ExampleHolder.class
+                        .getDeclaredField("value")
+                        .getAnnotation(io.swagger.v3.oas.annotations.media.Schema.class);
+
+        Optional<Schema> schema =
+                AnnotationsUtils.getSchemaFromAnnotation(
+                        schemaAnnotation,
+                        null,
+                        null,
+                        false,
+                        null,
+                        Schema.SchemaResolution.DEFAULT,
+                        null
+                );
+
+        assertTrue(schema.isPresent());
+        assertEquals(schema.get().getExample(), "5 lacs per annum");
+    }
+
 }