Fix json parser close tracking (#6865)

* std: fix json parsing with unmatched closing tokens

* std: fix swapped json parsing errors

1 files changed, 26 insertions, 5 deletions

diff --git a/lib/std/json.zig b/lib/std/json.zig
index 8ea91d8753..f6644fef9c 100644
--- a/lib/std/json.zig
+++ b/lib/std/json.zig
@@ -375,7 +375,7 @@ pub const StreamingParser = struct {
                 '}' => {
                     // unlikely
                     if (p.stack & 1 != object_bit) {
-                        return error.UnexpectedClosingBracket;
+                        return error.UnexpectedClosingBrace;
                     }
                     if (p.stack_used == 0) {
                         return error.TooManyClosingItems;
@@ -401,7 +401,7 @@ pub const StreamingParser = struct {
                 },
                 ']' => {
                     if (p.stack & 1 != array_bit) {
-                        return error.UnexpectedClosingBrace;
+                        return error.UnexpectedClosingBracket;
                     }
                     if (p.stack_used == 0) {
                         return error.TooManyClosingItems;
@@ -571,8 +571,11 @@ pub const StreamingParser = struct {
                     p.state = .ValueBeginNoClosing;
                 },
                 ']' => {
+                    if (p.stack & 1 != array_bit) {
+                        return error.UnexpectedClosingBracket;
+                    }
                     if (p.stack_used == 0) {
-                        return error.UnbalancedBrackets;
+                        return error.TooManyClosingItems;
                     }
 
                     p.state = .ValueEnd;
@@ -589,8 +592,12 @@ pub const StreamingParser = struct {
                     token.* = Token.ArrayEnd;
                 },
                 '}' => {
+                    // unlikely
+                    if (p.stack & 1 != object_bit) {
+                        return error.UnexpectedClosingBrace;
+                    }
                     if (p.stack_used == 0) {
-                        return error.UnbalancedBraces;
+                        return error.TooManyClosingItems;
                     }
 
                     p.state = .ValueEnd;
@@ -1189,6 +1196,15 @@ test "json.token" {
     testing.expect((try p.next()) == null);
 }
 
+test "json.token mismatched close" {
+    var p = TokenStream.init("[102, 111, 111 }");
+    checkNext(&p, .ArrayBegin);
+    checkNext(&p, .Number);
+    checkNext(&p, .Number);
+    checkNext(&p, .Number);
+    testing.expectError(error.UnexpectedClosingBrace, p.next());
+}
+
 /// Validate a JSON string. This does not limit number precision so a decoder may not necessarily
 /// be able to decode the string even if this returns true.
 pub fn validate(s: []const u8) bool {
@@ -1207,7 +1223,12 @@ pub fn validate(s: []const u8) bool {
 }
 
 test "json.validate" {
-    testing.expect(validate("{}"));
+    testing.expectEqual(true, validate("{}"));
+    testing.expectEqual(true, validate("[]"));
+    testing.expectEqual(true, validate("[{[[[[{}]]]]}]"));
+    testing.expectEqual(false, validate("{]"));
+    testing.expectEqual(false, validate("[}"));
+    testing.expectEqual(false, validate("{{{{[]}}}]"));
 }
 
 const Allocator = std.mem.Allocator;