test: add gloss-fetch test suite (red phase)

Eight test files cover the network layer's public and internal contract.
The boundary mock is `url-retrieve-synchronously', wrapped by a small
`testutil-gloss-fetch' helper that builds response buffers in the shape
the url library returns.

Tests cover the 200 happy paths (anaphora and SBIR fixtures), 404 to
:no-defs, 5xx and 4xx-other and malformed JSON to :server-error, 429 to
:rate-limited, nil-from-url to :unreachable, the libxml availability
probe (one-shot, signals user-error when absent), the registry walker
ordering, and the pure HTML strip helper across N/B/E.

Tests fail on missing `gloss-fetch--*' functions, as expected for red
phase.

1 files changed, 59 insertions, 0 deletions

diff --git a/tests/test-gloss-fetch--strip-html.el b/tests/test-gloss-fetch--strip-html.el
new file mode 100644
index 0000000..61f7e70
--- /dev/null
+++ b/tests/test-gloss-fetch--strip-html.el
@@ -0,0 +1,59 @@
+;;; test-gloss-fetch--strip-html.el --- HTML strip helper tests -*- lexical-binding: t -*-
+
+;; SPDX-License-Identifier: GPL-3.0-or-later
+
+;;; Commentary:
+;; `gloss-fetch--strip-html' converts a fragment of HTML to plain text
+;; using `libxml-parse-html-region' (no italic/bold preservation).
+;; Returns nil when libxml fails on the fragment so the caller can drop
+;; that sense.
+
+;;; Code:
+
+(require 'ert)
+(require 'gloss-fetch)
+
+(ert-deftest test-gloss-fetch-strip-html-plain-text-roundtrips ()
+  "Normal: a string with no markup comes back unchanged (modulo whitespace)."
+  (skip-unless (fboundp 'libxml-parse-html-region))
+  (should (equal (gloss-fetch--strip-html "Just plain text.")
+                 "Just plain text.")))
+
+(ert-deftest test-gloss-fetch-strip-html-removes-tags ()
+  "Normal: anchor and span tags are stripped, leaving inner text."
+  (skip-unless (fboundp 'libxml-parse-html-region))
+  (let ((stripped (gloss-fetch--strip-html
+                   "The <a href=\"/foo\">repetition</a> of a <i>phrase</i>.")))
+    (should (string-match-p "repetition" stripped))
+    (should (string-match-p "phrase" stripped))
+    (should-not (string-match-p "<" stripped))
+    (should-not (string-match-p "href" stripped))))
+
+(ert-deftest test-gloss-fetch-strip-html-empty-string-returns-empty ()
+  "Boundary: empty input returns an empty string (or nil)."
+  (skip-unless (fboundp 'libxml-parse-html-region))
+  (let ((result (gloss-fetch--strip-html "")))
+    (should (or (null result) (equal result "")))))
+
+(ert-deftest test-gloss-fetch-strip-html-entities-decoded ()
+  "Boundary: HTML entities decode to their characters."
+  (skip-unless (fboundp 'libxml-parse-html-region))
+  (let ((stripped (gloss-fetch--strip-html "Smith &amp; Wesson")))
+    (should (string-match-p "&" stripped))
+    (should-not (string-match-p "&amp;" stripped))))
+
+(ert-deftest test-gloss-fetch-strip-html-collapses-whitespace ()
+  "Boundary: runs of internal whitespace collapse to single spaces; result is trimmed."
+  (skip-unless (fboundp 'libxml-parse-html-region))
+  (let ((stripped (gloss-fetch--strip-html "  hello   <b>world</b>  ")))
+    (should (equal stripped "hello world"))))
+
+(ert-deftest test-gloss-fetch-strip-html-failure-returns-nil ()
+  "Error: when libxml-parse-html-region raises, return nil so the caller can drop the sense."
+  (skip-unless (fboundp 'libxml-parse-html-region))
+  (cl-letf (((symbol-function 'libxml-parse-html-region)
+             (lambda (&rest _) (error "libxml exploded"))))
+    (should-not (gloss-fetch--strip-html "any input"))))
+
+(provide 'test-gloss-fetch--strip-html)
+;;; test-gloss-fetch--strip-html.el ends here