Use configured regExp engine for $data pattern keyword

Author: mcollina

lib/vocabularies/code.ts

@@ -92,16 +92,21 @@ export function callValidateCode(
 
 const newRegExp = _`new RegExp`
 
-export function usePattern({gen, it: {opts}}: KeywordCxt, pattern: string): Name {
+export function usePattern({gen, it: {opts}}: KeywordCxt, pattern: string | Code): Code {
   const u = opts.unicodeRegExp ? "u" : ""
   const {regExp} = opts.code
-  const rx = regExp(pattern, u)
+  const regExpCode = regExp.code === "new RegExp" ? newRegExp : useFunc(gen, regExp)
+
+  if (typeof pattern == "string") {
+    const rx = regExp(pattern, u)
+    return gen.scopeValue("pattern", {
+      key: rx.toString(),
+      ref: rx,
+      code: _`${regExpCode}(${pattern}, ${u})`,
+    })
+  }
 
-  return gen.scopeValue("pattern", {
-    key: rx.toString(),
-    ref: rx,
-    code: _`${regExp.code === "new RegExp" ? newRegExp : useFunc(gen, regExp)}(${pattern}, ${u})`,
-  })
+  return _`${regExpCode}(${pattern}, ${u})`
 }
 
 export function validateArray(cxt: KeywordCxt): Name {

lib/vocabularies/validation/pattern.ts

@@ -17,10 +17,9 @@ const def: CodeKeywordDefinition = {
   $data: true,
   error,
   code(cxt: KeywordCxt) {
-    const {data, $data, schema, schemaCode, it} = cxt
+    const {data, $data, schema, schemaCode} = cxt
     // TODO regexp should be wrapped in try/catchs
-    const u = it.opts.unicodeRegExp ? "u" : ""
-    const regExp = $data ? _`(new RegExp(${schemaCode}, ${u}))` : usePattern(cxt, schema)
+    const regExp = usePattern(cxt, $data ? schemaCode : schema)
     cxt.fail$data(_`!${regExp}.test(${data})`)
   },
 }

spec/options/options_code.spec.ts

@@ -46,6 +46,30 @@ describe("code generation options", () => {
     })
   })
 
+  describe("regExp option", () => {
+    it("should use code.regExp for $data pattern values", () => {
+      const calls: {pattern: string; u: string}[] = []
+      const regExp: any = (pattern: string, u: string) => {
+        calls.push({pattern, u})
+        return {test: () => true}
+      }
+      regExp.code = "regExp"
+
+      const ajv = new _Ajv({$data: true, code: {regExp}})
+      const validate = ajv.compile({
+        type: "object",
+        properties: {
+          pattern: {type: "string"},
+          value: {type: "string", pattern: {$data: "1/pattern"}},
+        },
+      })
+
+      validate({pattern: "(", value: "abc"}).should.equal(true)
+      calls.should.have.length(1)
+      calls[0].pattern.should.equal("(")
+    })
+  })
+
   describe("passContext option", () => {
     let ajv: Ajv, contexts: any[]