feat: add persistent location search history

Successful searches are now remembered and offered as completion candidates the next time you run wttrin, listed after the configured defaults. Only successful fetches are saved, so typos and not-found locations never enter the history. A location already in wttrin-default-locations isn't duplicated into it. The list is capped at wttrin-location-history-max (default 20), oldest entries falling off first.

Persistence uses savehist: the history variable is registered with savehist-additional-variables, so enabling savehist-mode carries it across restarts with no custom file I/O. Without savehist it lasts the session.

Two commands manage the list: wttrin-remove-location-history drops one entry, wttrin-clear-location-history clears all.

I don't pass the history variable as the completing-read history argument, because the minibuffer would then save every typed string, including failed lookups. It stays a curated candidate source, updated only on success. I trim with butlast rather than seq-take to keep the Emacs 24.4 baseline.

1 files changed, 207 insertions, 0 deletions

diff --git a/tests/test-wttrin-location-history.el b/tests/test-wttrin-location-history.el
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+;;; test-wttrin-location-history.el --- Tests for location search history -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2024-2026 Craig Jennings
+
+;;; Commentary:
+;; Unit tests for the location search history feature: wttrin--add-to-location-history,
+;; wttrin--completion-candidates, wttrin-remove-location-history,
+;; wttrin-clear-location-history, and savehist integration.
+
+;;; Code:
+
+(require 'ert)
+(require 'cl-lib)
+(require 'wttrin)
+(require 'testutil-wttrin)
+
+;;; Setup and Teardown
+
+(defun test-wttrin-location-history-setup ()
+  "Setup: isolate history and defaults from the user's real config."
+  (testutil-wttrin-setup)
+  (setq wttrin--location-history nil))
+
+(defun test-wttrin-location-history-teardown ()
+  "Teardown: clear history."
+  (setq wttrin--location-history nil)
+  (testutil-wttrin-teardown))
+
+;;; wttrin--add-to-location-history
+
+(ert-deftest test-wttrin-location-history-normal-adds-new-location ()
+  "A new location is pushed onto the front of history."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin-default-locations '())
+            (wttrin--location-history nil))
+        (wttrin--add-to-location-history "Tokyo")
+        (should (equal '("Tokyo") wttrin--location-history)))
+    (test-wttrin-location-history-teardown)))
+
+(ert-deftest test-wttrin-location-history-normal-promotes-existing-to-front ()
+  "Re-adding an existing location moves it to the front without duplicating."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin-default-locations '())
+            (wttrin--location-history '("Paris" "Tokyo" "Berlin")))
+        (wttrin--add-to-location-history "Tokyo")
+        (should (equal '("Tokyo" "Paris" "Berlin") wttrin--location-history)))
+    (test-wttrin-location-history-teardown)))
+
+(ert-deftest test-wttrin-location-history-normal-skips-default-location ()
+  "A location already in defaults is not added to history."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin-default-locations '("Honolulu, HI"))
+            (wttrin--location-history nil))
+        (wttrin--add-to-location-history "Honolulu, HI")
+        (should (null wttrin--location-history)))
+    (test-wttrin-location-history-teardown)))
+
+(ert-deftest test-wttrin-location-history-boundary-trims-to-max ()
+  "History is trimmed to `wttrin-location-history-max', keeping the most recent."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin-default-locations '())
+            (wttrin-location-history-max 3)
+            (wttrin--location-history '("c" "b" "a")))
+        (wttrin--add-to-location-history "d")
+        (should (equal '("d" "c" "b") wttrin--location-history)))
+    (test-wttrin-location-history-teardown)))
+
+(ert-deftest test-wttrin-location-history-boundary-empty-history ()
+  "Adding to empty history yields a single-entry list."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin-default-locations '())
+            (wttrin--location-history nil))
+        (wttrin--add-to-location-history "Reykjavik")
+        (should (equal '("Reykjavik") wttrin--location-history)))
+    (test-wttrin-location-history-teardown)))
+
+(ert-deftest test-wttrin-location-history-boundary-max-zero-keeps-none ()
+  "A max of 0 results in empty history after a trim."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin-default-locations '())
+            (wttrin-location-history-max 0)
+            (wttrin--location-history nil))
+        (wttrin--add-to-location-history "Nowhere")
+        (should (null wttrin--location-history)))
+    (test-wttrin-location-history-teardown)))
+
+(ert-deftest test-wttrin-location-history-error-nil-location-no-op ()
+  "A nil location is a no-op."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin-default-locations '())
+            (wttrin--location-history '("Paris")))
+        (wttrin--add-to-location-history nil)
+        (should (equal '("Paris") wttrin--location-history)))
+    (test-wttrin-location-history-teardown)))
+
+(ert-deftest test-wttrin-location-history-error-empty-string-no-op ()
+  "An empty string is a no-op."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin-default-locations '())
+            (wttrin--location-history '("Paris")))
+        (wttrin--add-to-location-history "")
+        (should (equal '("Paris") wttrin--location-history)))
+    (test-wttrin-location-history-teardown)))
+
+;;; wttrin--completion-candidates
+
+(ert-deftest test-wttrin-location-history-normal-candidates-defaults-then-history ()
+  "Candidates list defaults first, then history."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin-default-locations '("Honolulu, HI" "Berkeley, CA"))
+            (wttrin--location-history '("Tokyo" "Paris")))
+        (should (equal '("Honolulu, HI" "Berkeley, CA" "Tokyo" "Paris")
+                       (wttrin--completion-candidates))))
+    (test-wttrin-location-history-teardown)))
+
+(ert-deftest test-wttrin-location-history-normal-candidates-only-defaults ()
+  "With empty history, candidates are just the defaults."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin-default-locations '("Honolulu, HI"))
+            (wttrin--location-history nil))
+        (should (equal '("Honolulu, HI") (wttrin--completion-candidates))))
+    (test-wttrin-location-history-teardown)))
+
+(ert-deftest test-wttrin-location-history-normal-candidates-only-history ()
+  "With empty defaults, candidates are just the history."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin-default-locations '())
+            (wttrin--location-history '("Tokyo")))
+        (should (equal '("Tokyo") (wttrin--completion-candidates))))
+    (test-wttrin-location-history-teardown)))
+
+;;; wttrin-remove-location-history
+
+(ert-deftest test-wttrin-location-history-normal-remove-entry ()
+  "Removing an entry drops it from history."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin--location-history '("Tokyo" "Paris" "Berlin")))
+        (cl-letf (((symbol-function 'message) (lambda (&rest _) nil)))
+          (wttrin-remove-location-history "Paris"))
+        (should (equal '("Tokyo" "Berlin") wttrin--location-history)))
+    (test-wttrin-location-history-teardown)))
+
+(ert-deftest test-wttrin-location-history-normal-remove-absent-no-op ()
+  "Removing an entry not present leaves history unchanged."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin--location-history '("Tokyo")))
+        (cl-letf (((symbol-function 'message) (lambda (&rest _) nil)))
+          (wttrin-remove-location-history "Mars"))
+        (should (equal '("Tokyo") wttrin--location-history)))
+    (test-wttrin-location-history-teardown)))
+
+(ert-deftest test-wttrin-location-history-boundary-remove-last-leaves-empty ()
+  "Removing the only entry leaves an empty list."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin--location-history '("Tokyo")))
+        (cl-letf (((symbol-function 'message) (lambda (&rest _) nil)))
+          (wttrin-remove-location-history "Tokyo"))
+        (should (null wttrin--location-history)))
+    (test-wttrin-location-history-teardown)))
+
+;;; wttrin-clear-location-history
+
+(ert-deftest test-wttrin-location-history-normal-clear-confirmed ()
+  "Confirming the prompt clears all history."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin--location-history '("Tokyo" "Paris")))
+        (cl-letf (((symbol-function 'yes-or-no-p) (lambda (&rest _) t))
+                  ((symbol-function 'message) (lambda (&rest _) nil)))
+          (wttrin-clear-location-history))
+        (should (null wttrin--location-history)))
+    (test-wttrin-location-history-teardown)))
+
+(ert-deftest test-wttrin-location-history-normal-clear-declined-keeps-history ()
+  "Declining the prompt leaves history intact."
+  (test-wttrin-location-history-setup)
+  (unwind-protect
+      (let ((wttrin--location-history '("Tokyo" "Paris")))
+        (cl-letf (((symbol-function 'yes-or-no-p) (lambda (&rest _) nil))
+                  ((symbol-function 'message) (lambda (&rest _) nil)))
+          (wttrin-clear-location-history))
+        (should (equal '("Tokyo" "Paris") wttrin--location-history)))
+    (test-wttrin-location-history-teardown)))
+
+;;; savehist integration
+
+(ert-deftest test-wttrin-location-history-integration-savehist-registers-variable ()
+  "Loading savehist registers wttrin--location-history for persistence."
+  (require 'savehist)
+  (should (memq 'wttrin--location-history savehist-additional-variables)))
+
+(provide 'test-wttrin-location-history)
+;;; test-wttrin-location-history.el ends here