1 files changed, 207 insertions, 0 deletions
diff --git a/tests/test-wttrin-location-history.el b/tests/test-wttrin-location-history.el
new file mode 100644
index 0000000..d03430d
--- /dev/null
+++ b/tests/test-wttrin-location-history.el
@@ -0,0 +1,207 @@
+;;; 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