Escape characters inline

.github/workflows/test.yml

@@ -26,6 +26,7 @@ jobs:
       - uses: actions/checkout@v6
       - run: echo "${{ matrix.python-version }}" > .python-version
       - uses: jdx/mise-action@v3
+      - run: mise install  # retry for network issues
       - run: ./build_and_test.sh
         shell: bash
       - name: Publish Test Report

.github/workflows/test_min.yml

@@ -23,6 +23,7 @@ jobs:
       - uses: actions/checkout@v6
       - run: echo "${{ matrix.python-version }}" > .python-version
       - uses: jdx/mise-action@v3
+      - run: mise install  # retry for network issues
       - run: python ./generate_prod_min.py
       - run: ./build_and_test.sh
         shell: bash

.github/workflows/tidy_code_and_update_markdown_snippets.yml

@@ -8,6 +8,7 @@ jobs:
     steps:
     - uses: actions/checkout@v6
     - uses: jdx/mise-action@v3
+    - run: mise install  # retry for network issues
     - run: ./tidy_code.sh
     - run: ./run_mdsnippets.sh
       shell: bash

approvaltests/namer/inline_python_reporter.py

@@ -38,6 +38,36 @@ def escape_backslashes(text: str) -> str:
     return text.replace("\\", "\\\\")
 
 
+def escape_control_characters(text: str) -> str:
+    if not text:
+        return text
+
+    translation_table = str.maketrans(
+        {
+            "\x00": "\\x00",  # Null
+            "\x08": "\\b",  # Backspace
+            "\x0b": "\\v",  # Vertical tab
+            "\x0c": "\\f",  # Form feed
+            "\x1b": "\\x1b",  # Escape
+            "\x7f": "\\x7f",  # Delete
+            "\u00a0": "\\u00a0",  # Non-breaking space
+            "\u200b": "\\u200b",  # Zero-width space
+            "\u200c": "\\u200c",  # Zero-width non-joiner
+            "\u200d": "\\u200d",  # Zero-width joiner
+            "\u200e": "\\u200e",  # Left-to-right mark
+            "\u200f": "\\u200f",  # Right-to-left mark
+            "\u202c": "\\u202c",  # Pop directional formatting
+            "\u202d": "\\u202d",  # Left-to-right override
+            "\u202e": "\\u202e",  # Right-to-left override
+            "\u2028": "\\u2028",  # Line separator
+            "\u2029": "\\u2029",  # Paragraph separator
+            "\ufeff": "\\ufeff",  # Byte order mark
+        }
+    )
+
+    return text.translate(translation_table)
+
+
 class InlinePythonReporter(Reporter):
     def __init__(
         self,
@@ -64,10 +94,9 @@ def create_received_file(self, received_path: str, test_source_file: str) -> str
 
         original_received_text = Path(received_path).read_text(encoding="utf-8")[:-1]
         received_text = original_received_text + self.footer
-        # Handle preceding whitespace consistently across all lines.
         received_text = handle_preceeding_whitespace(received_text)
-        # Escape backslashes to avoid accidental escape sequences in the docstring.
         received_text = escape_backslashes(received_text)
+        received_text = escape_control_characters(received_text)
         method_name = StackFrameNamer.get_test_frame().function
         if detect_trailing_whitespace(original_received_text):
             trailing_comment = "  # Warning: Editors may remove trailing spaces, causing this test to fail"

internal_documentation/micro_features/inline_approvals_whitespace.md

@@ -28,6 +28,31 @@ How inline approvals handles whitespace in docstrings and verified strings, incl
 4. Escape characters
    Backslashes are special in docstrings. So the reporter will escape them with another backslash.
 
+5. Control characters
+   If a control character is in the string, we want to represent it explicitly. For example `\u200f`.
+
+   The control characters we care about are:
+   - `\u200f` (right-to-left marker)
+   - `\0` (null)
+  - Vertical tab (\v, 0x0B)
+  - Form feed (\f, 0x0C)
+  - Escape (\x1b, 0x1B)
+  - Right-to-Left Override (RLO, U+202E) - Already being tested
+  - Left-to-Right Override (LRO, U+202D)
+  - Right-to-Left Mark (RLM, U+200F)
+  - Left-to-Right Mark (LRM, U+200E)
+  - Pop Directional Formatting (PDF, U+202C)
+  - Zero-Width Space (ZWSP, U+200B)
+  - Zero-Width Non-Joiner (ZWNJ, U+200C)
+  - Zero-Width Joiner (ZWJ, U+200D)
+  - Non-breaking space (NBSP, U+00A0)
+  - Byte Order Mark (BOM, U+FEFF)
+  - Backspace (\b, 0x08)
+  - Delete (DEL, 0x7F)
+  - Line Separator (U+2028)
+  - Paragraph Separator (U+2029)
+
+
 ## Special markers
 
 If the first line is `<<approvaltests:preserve-leading-whitespace>>`, then remove it before verifying. This is only  true if it's the first line.