Define RST219 Inline substitution_reference start-string without end-string.

Author: peterjc

README.rst

@@ -106,6 +106,7 @@ RST215 Inline interpreted text or phrase reference start-string without end-stri
 RST216 Multiple roles in interpreted text (both prefix and suffix present; only one allowed).
 RST217 Mismatch: both interpreted text role suffix and reference suffix.
 RST218 Literal block expected; none found.
+RST219 Inline substitution_reference start-string without end-string.
 RST299 Previously unseen warning, not yet assigned a unique code.
 ====== =======================================================================
 
@@ -219,7 +220,7 @@ Version History
 ======= ========== ===========================================================
 Version Released   Changes
 ------- ---------- -----------------------------------------------------------
-v0.0.13 2019-12-26 - Adds ``RST218``.
+v0.0.13 2019-12-26 - Adds ``RST218`` and ``RST219``.
 v0.0.12 2019-11-18 - Adds ``RST213`` to ``RST217``.
 v0.0.11 2019-08-07 - Configuration options to define additional directives and
                      roles (e.g. from Sphinx) for ``RST303`` and ``RST304``.

flake8_rst_docstrings.py

@@ -177,6 +177,7 @@ def tokenize_open(filename):
     "Multiple roles in interpreted text (both prefix and suffix present; only one allowed).": 16,  # noqa: E501
     "Mismatch: both interpreted text role suffix and reference suffix.": 17,
     "Literal block expected; none found.": 18,
+    "Inline substitution_reference start-string without end-string.": 19,
 }
 
 # Level 3 - error

tests/RST219/bad_sub_ref.py

@@ -0,0 +1,17 @@
+r"""Print 'Hello world' to the terminal.
+
+RST supports inline substitution references,
+and the string |000...00> looks a bit like one
+so triggers an error:
+
+    $ flake8 --select RST RST219/bad_sub_ref.py
+    RST219/bad_sub_ref.py:4:1: RST219 Inline substitution_reference start-string without end-string
+
+One potential way to avoid this using ``|000...00>``
+instead (wrapping in backticks as a inline literal).
+
+Better, escape the opening pipe as \|000...00>
+instead.
+"""
+
+print("Hello world")