Close #1699: support regex flags in tags.Pattern

Author: knoan

src/factories/MetadataCommentTagFactory.ts

@@ -524,21 +524,56 @@ const PARSER: Record<
       ],
     };
   },
-  pattern: ({ value }) => ({
-    string: [
-      {
-        name: `Pattern<${JSON.stringify(value)}>`,
-        target: "string",
-        kind: "pattern",
-        value: value,
-        validate: `RegExp(${JSON.stringify(value)}).test($input)`,
-        exclusive: ["format"],
-        schema: {
-          pattern: value,
+  pattern: ({ value }) => {
+    // Support regex literal syntax: /pattern/flags
+    const match = value.match(/^\/(.*)\/([dgimsuy]*)$/);
+    if (match !== null) {
+      const [, pattern, flags] = match;
+      return {
+        string: [
+          {
+            name:
+              flags === ""
+                ? `Pattern<${JSON.stringify(pattern)}>`
+                : `Pattern<${JSON.stringify(pattern)}, ${JSON.stringify(flags)}>`,
+            target: "string",
+            kind: "pattern",
+            value: pattern,
+            validate:
+              flags === ""
+                ? `RegExp(${JSON.stringify(pattern)}).test($input)`
+                : `RegExp(${JSON.stringify(pattern)}, ${JSON.stringify(flags)}).test($input)`,
+            exclusive: ["format"],
+            schema:
+              flags === ""
+                ? {
+                    pattern: pattern,
+                  }
+                : {
+                    pattern: pattern,
+                    "x-pattern-flags": flags,
+                  },
+          },
+        ],
+      };
+    }
+    // Legacy format: just the pattern (no flags)
+    return {
+      string: [
+        {
+          name: `Pattern<${JSON.stringify(value)}>`,
+          target: "string",
+          kind: "pattern",
+          value: value,
+          validate: `RegExp(${JSON.stringify(value)}).test($input)`,
+          exclusive: ["format"],
+          schema: {
+            pattern: value,
+          },
         },
-      },
-    ],
-  }),
+      ],
+    };
+  },
   length: (props) => ({
     string: [
       {

src/programmers/RandomProgrammer.ts

@@ -504,22 +504,35 @@ export namespace RandomProgrammer {
                 .join("")}`,
               arguments: [],
             };
-          } else if (string.pattern !== undefined)
+          } else if (string.pattern !== undefined) {
+            const flags: string | undefined = (
+              schema as OpenApi.IJsonSchema.IString & {
+                "x-pattern-flags"?: string;
+              }
+            )["x-pattern-flags"];
             return {
               method: "pattern",
               internal: "randomPattern",
               arguments: [
                 ts.factory.createNewExpression(
                   ts.factory.createIdentifier("RegExp"),
                   undefined,
-                  [
-                    ts.factory.createStringLiteral(
-                      (schema as OpenApi.IJsonSchema.IString).pattern!,
-                    ),
-                  ],
+                  flags !== undefined
+                    ? [
+                        ts.factory.createStringLiteral(
+                          (schema as OpenApi.IJsonSchema.IString).pattern!,
+                        ),
+                        ts.factory.createStringLiteral(flags),
+                      ]
+                    : [
+                        ts.factory.createStringLiteral(
+                          (schema as OpenApi.IJsonSchema.IString).pattern!,
+                        ),
+                      ],
                 ),
               ],
             };
+          }
         } else if (props.atomic.type === "number") {
           const number:
             | OpenApi.IJsonSchema.INumber

src/tags/Pattern.ts

@@ -13,20 +13,42 @@ import { TagBase } from "./TagBase";
  * type HexColor = string & Pattern<"^#[0-9A-Fa-f]{6}$">; // #FF5733
  * ```
  *
+ * You can also specify regex flags as a second parameter:
+ *
+ * ```ts
+ * // Case-insensitive matching
+ * type CaseInsensitive = string & Pattern<"^hello$", "i">;
+ *
+ * // Unicode property escapes (requires 'u' flag)
+ * type Identifier = string & Pattern<"^[\\p{ID_Start}_$][\\p{ID_Continue}_$]*$", "u">;
+ * ```
+ *
+ * Supported flags: `d`, `g`, `i`, `m`, `s`, `u`, `v`, `y` (can be combined)
+ *
  * Note: This tag is mutually exclusive with the Format tag. You cannot use both
  * Pattern and Format on the same type.
  *
  * @author Jeongho Nam - https://github.com/samchon
  */
-export type Pattern<Value extends string> = TagBase<{
+export type Pattern<
+  Value extends string,
+  Flags extends string = "",
+> = TagBase<{
   target: "string";
   kind: "pattern";
   value: Value;
-  validate: `RegExp("${Serialize<Value>}").test($input)`;
+  validate: Flags extends ""
+    ? `RegExp("${Serialize<Value>}").test($input)`
+    : `RegExp("${Serialize<Value>}", "${Flags}").test($input)`;
   exclusive: ["format", "pattern"];
-  schema: {
-    pattern: Value;
-  };
+  schema: Flags extends ""
+    ? {
+        pattern: Value;
+      }
+    : {
+        pattern: Value;
+        "x-pattern-flags": Flags;
+      };
 }>;
 
 /// reference: https://github.com/type-challenges/type-challenges/issues/22394#issuecomment-1397158205

test/src/structures/CommentTagPatternFlags.ts

@@ -0,0 +1,36 @@
+import { Spoiler } from "../helpers/Spoiler";
+
+export interface CommentTagPatternFlags {
+  /** @pattern /^hello$/i */
+  caseInsensitive: string;
+
+  /** @pattern /^hello$/m */
+  multiline: string;
+
+  /** @pattern /^[a-z]+$/im */
+  multipleFlags: string;
+}
+export namespace CommentTagPatternFlags {
+  export function generate(): CommentTagPatternFlags {
+    return {
+      caseInsensitive: "HELLO",
+      multiline: "hello",
+      multipleFlags: "hello",
+    };
+  }
+
+  export const SPOILERS: Spoiler<CommentTagPatternFlags>[] = [
+    (input) => {
+      input.caseInsensitive = "world";
+      return ["$input.caseInsensitive"];
+    },
+    (input) => {
+      input.multiline = "world";
+      return ["$input.multiline"];
+    },
+    (input) => {
+      input.multipleFlags = "123";
+      return ["$input.multipleFlags"];
+    },
+  ];
+}

test/src/structures/TypeTagPatternFlags.ts

@@ -0,0 +1,38 @@
+import typia from "typia";
+
+import { Spoiler } from "../helpers/Spoiler";
+
+export interface TypeTagPatternFlags {
+  // Case-insensitive matching
+  caseInsensitive: string & typia.tags.Pattern<"^hello$", "i">;
+
+  // Multiline flag
+  multiline: string & typia.tags.Pattern<"^hello$", "m">;
+
+  // Multiple flags combined
+  multipleFlags: string & typia.tags.Pattern<"^[a-z]+$", "im">;
+}
+export namespace TypeTagPatternFlags {
+  export function generate(): TypeTagPatternFlags {
+    return {
+      caseInsensitive: "HELLO",
+      multiline: "hello",
+      multipleFlags: "hello",
+    };
+  }
+
+  export const SPOILERS: Spoiler<TypeTagPatternFlags>[] = [
+    (input) => {
+      input.caseInsensitive = "world";
+      return ["$input.caseInsensitive"];
+    },
+    (input) => {
+      input.multiline = "world";
+      return ["$input.multiline"];
+    },
+    (input) => {
+      input.multipleFlags = "123";
+      return ["$input.multipleFlags"];
+    },
+  ];
+}