From f399e3c921ae6a95964cea2bafcfd1aa05dc27ad Mon Sep 17 00:00:00 2001
From: Josh <jcjohnson77@gmail.com>
Date: Wed, 16 Feb 2022 13:33:26 -0500
Subject: [PATCH] WIP: Better unknown handling configuration

---
 lib/index.d.ts    |  7 ++++++-
 lib/types/keys.js | 18 +++++++++++++++---
 test/validator.js | 41 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 62 insertions(+), 4 deletions(-)

diff --git a/lib/index.d.ts b/lib/index.d.ts
index d6218c660..e3f662858 100644
--- a/lib/index.d.ts
+++ b/lib/index.d.ts
@@ -30,6 +30,8 @@ declare namespace Joi {
 
     type PresenceMode = 'optional' | 'required' | 'forbidden';
 
+    type AllowMode = boolean | 'allowed' | 'forbidden' | 'warn';
+
     interface ErrorFormattingOptions {
         /**
          * when true, error message templates will escape special characters to HTML entities, for security purposes.
@@ -104,7 +106,10 @@ declare namespace Joi {
          *
          * @default false
          */
-        allowUnknown?: boolean;
+        allowUnknown?: AllowMode | {
+            mode: AllowMode,
+            type?: string,
+        };
         /**
          * when true, schema caching is enabled (for schemas with explicit caching rules).
          *
diff --git a/lib/types/keys.js b/lib/types/keys.js
index 8f8a950f2..416eaeaa6 100755
--- a/lib/types/keys.js
+++ b/lib/types/keys.js
@@ -975,11 +975,14 @@ internals.unknown = function (schema, value, unprocessed, errors, state, prefs)
         }
     }
 
-    const forbidUnknown = !Common.default(schema._flags.unknown, prefs.allowUnknown);
-    if (forbidUnknown) {
+    const allowUnknown = Common.default(schema._flags.unknown, prefs.allowUnknown);
+    const allowUnknownIsObject = typeof allowUnknown === 'object' && !Array.isArray(allowUnknown) && allowUnknown !== null;
+    const type = (allowUnknownIsObject ? allowUnknown.type : undefined) || 'object.unknown';
+
+    if (allowUnknown === false || allowUnknown === undefined || allowUnknown === 'forbidden' || (allowUnknownIsObject && allowUnknown.mode === 'forbidden')) {
         for (const unprocessedKey of unprocessed) {
             const localState = state.localize([...state.path, unprocessedKey], []);
-            const report = schema.$_createError('object.unknown', value[unprocessedKey], { child: unprocessedKey }, localState, prefs, { flags: false });
+            const report = schema.$_createError(type, value[unprocessedKey], { child: unprocessedKey }, localState, prefs, { flags: false });
             if (prefs.abortEarly) {
                 return { value, errors: report };
             }
@@ -987,6 +990,15 @@ internals.unknown = function (schema, value, unprocessed, errors, state, prefs)
             errors.push(report);
         }
     }
+    else if (allowUnknown === 'warn' || (allowUnknownIsObject && allowUnknown.mode === 'warn')) {
+
+        for (const unprocessedKey of unprocessed) {
+            const localState = state.localize([...state.path, unprocessedKey], []);
+            const report = schema.$_createError(type, value[unprocessedKey], { child: unprocessedKey }, localState, prefs, { flags: false });
+
+            state.mainstay.warnings.push(report);
+        }
+    }
 };
 
 
diff --git a/test/validator.js b/test/validator.js
index f4bc23269..cf78c9e49 100755
--- a/test/validator.js
+++ b/test/validator.js
@@ -508,6 +508,47 @@ describe('Validator', () => {
                 }
             });
         });
+
+        it('reports warnings with nested options', () => {
+
+            const schema = Joi.object({
+                nested: Joi.object({
+                    validKey: Joi.string()
+                })
+            }).warning('custom.x').message('test');
+
+            const allowUnknown = {
+                mode: 'warn',
+                type: 'custom.x'
+            };
+
+            const input = {
+                nested: {
+                    validKey: 'some string',
+                    invalidKey: 'oh no!'
+                }
+            };
+
+            const { value, error, warning } = schema.validate(input, { allowUnknown });
+            expect(value).to.equal(input);
+            expect(error).to.not.exist();
+            expect(warning).to.equal({
+                message: 'test',
+                details: [
+                    {
+                        message: 'test',
+                        path: ['nested', 'invalidKey'],
+                        type: 'custom.x',
+                        context: {
+                            child: 'invalidKey',
+                            key: 'invalidKey',
+                            label: 'nested.invalidKey',
+                            value: 'oh no!'
+                        }
+                    }
+                ]
+            });
+        });
     });
 
     describe('Shadow', () => {