feat: add wttrin-display-options for wttr.in flag customization (closes #3)

wttr.in accepts single-character flags appended to the URL that control what the report looks like — no Follow line (F), narrow output (n), quiet mode (q), forecast horizon (0/1/2), console-glyph mode (d), and so on. Until now wttrin always used the same default report shape with no way to opt into these.

Added a `wttrin-display-options` defcustom that takes a string of concatenated flags, e.g. "0Fq" for current weather only with no Follow line and no header. The flags get appended to every request via `wttrin--build-url`. The defcustom defaults to nil so existing users see no change.

I excluded `A` and `T` from the recommended set in the docstring since wttrin needs ANSI output for the xterm-color rendering to produce the colored glyphs. The user could still pass them, but the docstring nudges them away.

Tests cover the normal cases (single, multi-flag, with and without unit system), the boundaries (nil and empty string both leave the URL unchanged from baseline, single character works), and a sanity check that the new flags slot in after the always-on `A`. Existing build-url tests stay green because they don't bind the new variable, and the default is nil.

Also added `.claude/` to .gitignore — the scheduled-tasks lockfile from local wakeup scheduling shouldn't be tracked.

4 files changed, 81 insertions, 1 deletions

diff --git a/.gitignore b/.gitignore
index aead5da..3d24fd3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 /todo.org
 /.ai/
+/.claude/
 /.stignore
 /.eask/
 /.coverage/
diff --git a/README.org b/README.org
index ea4aaf0..e3e5c98 100644
--- a/README.org
+++ b/README.org
@@ -174,6 +174,17 @@ Wttrin's default is to select the unit system appropriate for the location you q
   (setq wttrin-unit-system nil) ;; the default of using units appropriate for the queried location.
 #+end_src
 
+*** Display Options
+wttr.in supports a handful of single-character flags that change what the report looks like. Concatenate them in =wttrin-display-options= and they'll be appended to every request:
+
+#+begin_src emacs-lisp
+  (setq wttrin-display-options "0Fq")  ;; current weather only, no Follow line, no header
+  (setq wttrin-display-options "n")    ;; narrow version (only day and night)
+  (setq wttrin-display-options nil)    ;; default (all options off)
+#+end_src
+
+The full list of flags is at https://wttr.in/:help. Skip =A= and =T= — wttrin manages ANSI output internally so the colored glyphs render correctly.
+
 *** Cache Settings
 Wttrin caches weather data and refreshes it in the background. By default it refreshes every hour and keeps up to 50 entries. You can adjust both:
 
diff --git a/tests/test-wttrin--build-url.el b/tests/test-wttrin--build-url.el
index b19ede1..9bb514a 100644
--- a/tests/test-wttrin--build-url.el
+++ b/tests/test-wttrin--build-url.el
@@ -91,6 +91,50 @@ The @ symbol should be URL-encoded as %40."
       (should (string-prefix-p "https://wttr.in/" url))
       (should (string-match-p "%40github\\.com" url)))))
 
+;;; Display Options Cases
+
+(ert-deftest test-wttrin--build-url-normal-display-options-appended-after-A ()
+  "Display options string is appended after the A flag."
+  (let ((wttrin-unit-system nil)
+        (wttrin-display-options "0Fq"))
+    (should (string= "https://wttr.in/Paris?A0Fq"
+                     (wttrin--build-url "Paris")))))
+
+(ert-deftest test-wttrin--build-url-normal-display-options-with-unit-system ()
+  "Display options coexist with unit system, both inside the same query string."
+  (let ((wttrin-unit-system "m")
+        (wttrin-display-options "0F"))
+    (should (string= "https://wttr.in/Tokyo?mA0F"
+                     (wttrin--build-url "Tokyo")))))
+
+(ert-deftest test-wttrin--build-url-normal-display-options-narrow-quiet ()
+  "Common combination: narrow + quiet."
+  (let ((wttrin-unit-system nil)
+        (wttrin-display-options "nq"))
+    (should (string= "https://wttr.in/SFO?Anq"
+                     (wttrin--build-url "SFO")))))
+
+(ert-deftest test-wttrin--build-url-boundary-display-options-nil-omits-flags ()
+  "Nil display-options leaves URL unchanged from baseline."
+  (let ((wttrin-unit-system nil)
+        (wttrin-display-options nil))
+    (should (string= "https://wttr.in/Paris?A"
+                     (wttrin--build-url "Paris")))))
+
+(ert-deftest test-wttrin--build-url-boundary-display-options-empty-string-omits-flags ()
+  "Empty display-options string is treated like nil."
+  (let ((wttrin-unit-system nil)
+        (wttrin-display-options ""))
+    (should (string= "https://wttr.in/Paris?A"
+                     (wttrin--build-url "Paris")))))
+
+(ert-deftest test-wttrin--build-url-boundary-display-options-single-character ()
+  "Single-character display-options works."
+  (let ((wttrin-unit-system nil)
+        (wttrin-display-options "F"))
+    (should (string= "https://wttr.in/London?AF"
+                     (wttrin--build-url "London")))))
+
 ;;; Error Cases
 
 (ert-deftest test-wttrin--build-url-error-nil-query-signals-error ()
diff --git a/wttrin.el b/wttrin.el
index 3caa178..7e67af3 100644
--- a/wttrin.el
+++ b/wttrin.el
@@ -96,6 +96,29 @@ units (default)."
   :group 'wttrin
   :type 'string)
 
+(defcustom wttrin-display-options nil
+  "wttr.in display option flags concatenated as a string.
+Each character is a wttr.in flag, as documented at https://wttr.in/:help.
+Common options:
+
+  0    only current weather (no forecast)
+  1    current weather + today's forecast
+  2    current weather + today's + tomorrow's forecast
+  d    restrict output to standard console font glyphs
+  F    do not show the \"Follow\" line
+  n    narrow version (only day and night)
+  q    quiet version (no \"Weather report\" text)
+  Q    superquiet version (no \"Weather report\", no city name)
+
+Example: \"0Fq\" gives current weather only with no Follow line and no
+header.  Default nil means no extra options.
+
+Avoid \"A\" and \"T\" — wttrin manages ANSI output internally so the
+xterm-color rendering produces the colored glyphs."
+  :group 'wttrin
+  :type '(choice (const :tag "None" nil)
+                 (string :tag "Options")))
+
 
 (define-obsolete-variable-alias 'wttrin-cache-ttl 'wttrin-refresh-interval "0.3.0")
 
@@ -271,7 +294,8 @@ Returns \"just now\" for <60s, \"X minutes ago\", \"X hours ago\", or \"X days a
   (concat "https://wttr.in/"
           (url-hexify-string query)
           (wttrin-additional-url-params)
-          "A"))
+          "A"
+          (or wttrin-display-options "")))
 
 (defun wttrin--extract-http-status ()
   "Return the HTTP status code from the current buffer, or nil.