fix: reference resolution issue with base URI change, fixes #1414

lib/compile/index.ts

@@ -246,7 +246,7 @@ export function resolveSchema(
 ): SchemaEnv | undefined {
   const p = URI.parse(ref)
   const refPath = _getFullPath(p)
-  const baseId = getFullPath(root.baseId)
+  let baseId = getFullPath(root.baseId)
   // TODO `Object.keys(root.schema).length > 0` should not be needed - but removing breaks 2 tests
   if (Object.keys(root.schema).length > 0 && refPath === baseId) {
     return getJsonPointer.call(this, p, root)
@@ -262,7 +262,11 @@ export function resolveSchema(
 
   if (typeof schOrRef?.schema !== "object") return
   if (!schOrRef.validate) compileSchema.call(this, schOrRef)
-  if (id === normalizeId(ref)) return new SchemaEnv({schema: schOrRef.schema, root, baseId})
+  if (id === normalizeId(ref)) {
+    const {schema} = schOrRef
+    if (schema.$id) baseId = resolveUrl(baseId, schema.$id)
+    return new SchemaEnv({schema, root, baseId})
+  }
   return getJsonPointer.call(this, p, schOrRef)
 }
 

spec/issues/1414_base_uri_change.spec.ts

@@ -0,0 +1,35 @@
+import _Ajv from "../ajv"
+import assert = require("assert")
+
+const schema1 = {
+  $id: "one",
+  type: "object",
+  properties: {
+    foo: {$ref: "#/definitions/foo"},
+  },
+  definitions: {
+    foo: {$ref: "two"},
+  },
+}
+
+const schema2 = {
+  $id: "two",
+  type: "object",
+  properties: {
+    bar: {$ref: "#/definitions/bar"},
+  },
+  definitions: {
+    bar: {type: "string"},
+  },
+}
+
+describe("issue 1414: base URI change", () => {
+  it("should compile schema", () => {
+    const ajv = new _Ajv()
+    ajv.addSchema(schema2)
+    const validate = ajv.compile(schema1)
+    assert.strictEqual(typeof validate, "function")
+    assert.strictEqual(validate({foo: {bar: 1}}), false)
+    assert.strictEqual(validate({foo: {bar: "1"}}), true)
+  })
+})