IPI protection

main_test.go

@@ -1851,6 +1851,95 @@ func TestFetchContextWindowFallbackConfig(t *testing.T) {
   }
 }
 
+func TestFilterText(t *testing.T) {
+  cases := []struct {
+    name     string
+    input    string
+    expected string
+  }{
+    {
+      name:     "ASCII printable, spaces, tabs, newlines",
+      input:    "Hello World!\t123\nLine 2 ~`@#$%",
+      expected: "Hello World!\t123\nLine 2 ~`@#$%",
+    },
+    {
+      name:     "CRLF normalization",
+      input:    "line1\r\nline2\r\n",
+      expected: "line1\nline2\n",
+    },
+    {
+      name:     "Unicode printable letters, numbers, punctuation",
+      input:    "こんにちは世界！ Привет мир! 123 αβγ €$¥",
+      expected: "こんにちは世界！ Привет мир! 123 αβγ €$¥",
+    },
+    {
+      name:     "Control characters stripped",
+      input:    "null\x00bell\x07esc\x1b[31mred\x1b[0m\x7fdel",
+      expected: "nullbellesc[31mred[0mdel",
+    },
+    {
+      name:     "Zero-width and format characters stripped",
+      input:    "hidden\u200Binjection\u200Cand\u200Djoiner\uFEFFbom\u202Ebidi\U000E0001tag",
+      expected: "hiddeninjectionandjoinerbombiditag",
+    },
+    {
+      name:     "Space-like unicode characters stripped",
+      input:    "nbsp\u00A0space\u2000enquad\u2001emquad\u2009thin\u202Fnarrow\u3000ideo\u1680ogham\u2028lsep\u2029psep",
+      expected: "nbspspaceenquademquadthinnarrowideooghamlseppsep",
+    },
+  }
+
+  for _, tc := range cases {
+    t.Run(tc.name, func(t *testing.T) {
+      got := filterText(tc.input)
+      if got != tc.expected {
+        t.Errorf("filterText(%q) = %q, expected %q", tc.input, got, tc.expected)
+      }
+    })
+  }
+}
+
+func TestSanitizeMessagesWithInvisibles(t *testing.T) {
+  msgs := []Message{
+    {
+      Role: "assistant",
+      ToolCalls: []ToolCall{
+        {
+          ID:   "call_1",
+          Type: "function",
+          Function: struct {
+            Name      string `json:"name"`
+            Arguments string `json:"arguments"`
+          }{
+            Name:      "shell_exec",
+            Arguments: "{\"command\": \"cat\u200B \u00A0file.txt\"}",
+          },
+        },
+      },
+    },
+    {
+      Role:       "tool",
+      ToolCallID: "call_1",
+      Content:    strp("output\u200B\x00with\u00A0invisible\r\nexit: 0"),
+    },
+  }
+
+  sanitizeMessages(msgs)
+
+  tcArgs := msgs[0].ToolCalls[0].Function.Arguments
+  if strings.Contains(tcArgs, "\u200B") || strings.Contains(tcArgs, "\u00A0") {
+    t.Errorf("Tool call arguments still contain invisible characters: %q", tcArgs)
+  }
+
+  toolContent := *msgs[1].Content
+  if strings.Contains(toolContent, "\u200B") || strings.Contains(toolContent, "\x00") || strings.Contains(toolContent, "\u00A0") || strings.Contains(toolContent, "\r") {
+    t.Errorf("Tool content still contains invisible characters: %q", toolContent)
+  }
+  if !strings.Contains(toolContent, "outputwithinvisible\nexit: 0") {
+    t.Errorf("Tool content unexpected: %q", toolContent)
+  }
+}
+