feat(calendar-sync): dispatch Google calendars through API helper

The Python helper from d6a995b could fetch and render on its own, but nothing in Emacs called it. This wires it in. Each entry in calendar-sync-calendars now takes a :fetcher key. 'api routes through the helper, and the default 'ics keeps the existing curl + Elisp parser path. Proton and any plain .ics feed work unchanged because the key defaults to 'ics.

The 'api path reads :account and :calendar-id off the calendar plist, builds the helper command (honoring the past/future window and the calendar-sync-skip-declined toggle), and runs it through make-process. The script writes the org file directly, so the sentinel only handles state bookkeeping and failure reporting, the same as the .ics worker.

I split the old --sync-calendar body into --sync-calendar-ics and turned --sync-calendar into a dispatcher. The command builder and script-path resolution are pure functions, tested directly. The dispatch routing is tested with both leaf syncers stubbed, so no process runs. I added 14 tests across the two new files, and the full suite is green.

Running the 'api path still needs the one-time OAuth bootstrap from docs/calendar-sync-api-setup.org.

1 files changed, 99 insertions, 0 deletions

diff --git a/tests/test-calendar-sync--api-command.el b/tests/test-calendar-sync--api-command.el
new file mode 100644
index 00000000..21c09f51
--- /dev/null
+++ b/tests/test-calendar-sync--api-command.el
@@ -0,0 +1,99 @@
+;;; test-calendar-sync--api-command.el --- Tests for API command builder  -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Unit tests for the Google Calendar API fetch path's pure helpers:
+;; `calendar-sync--api-script' (resolves the helper script path) and
+;; `calendar-sync--api-command' (builds the make-process argument list).
+;; Covers Normal, Boundary, and Error cases.
+
+;;; Code:
+
+(require 'ert)
+(require 'calendar-sync)
+
+;;; calendar-sync--api-script
+
+(ert-deftest test-calendar-sync--api-script-normal-resolves-to-helper ()
+  "Normal: the script path ends with the helper filename and is absolute."
+  (let ((path (calendar-sync--api-script)))
+    (should (file-name-absolute-p path))
+    (should (string-suffix-p "scripts/calendar_sync_api.py" path))))
+
+(ert-deftest test-calendar-sync--api-script-normal-no-dotdot ()
+  "Normal: the resolved path is collapsed (no literal ../ segment)."
+  (let ((path (calendar-sync--api-script)))
+    (should-not (string-match-p "\\.\\./" path))))
+
+;;; calendar-sync--api-command — Normal
+
+(ert-deftest test-calendar-sync--api-command-normal-structure ()
+  "Normal: command starts with the python binary + script, then the flags."
+  (let ((calendar-sync-python-command "python3")
+        (calendar-sync-past-months 3)
+        (calendar-sync-future-months 12)
+        (calendar-sync-skip-declined t))
+    (let ((cmd (calendar-sync--api-command "work" "primary" "/tmp/out.org")))
+      (should (equal (nth 0 cmd) "python3"))
+      (should (string-suffix-p "calendar_sync_api.py" (nth 1 cmd)))
+      (should (member "--account" cmd))
+      (should (member "work" cmd))
+      (should (member "--calendar-id" cmd))
+      (should (member "primary" cmd))
+      (should (member "--output" cmd))
+      (should (member "/tmp/out.org" cmd)))))
+
+(ert-deftest test-calendar-sync--api-command-normal-flag-pairing ()
+  "Normal: each value immediately follows its flag."
+  (let ((calendar-sync-python-command "python3")
+        (calendar-sync-skip-declined t))
+    (let ((cmd (calendar-sync--api-command "personal" "abc123" "/tmp/gcal.org")))
+      (should (equal "personal" (nth (1+ (cl-position "--account" cmd :test #'equal)) cmd)))
+      (should (equal "abc123" (nth (1+ (cl-position "--calendar-id" cmd :test #'equal)) cmd)))
+      (should (equal "/tmp/gcal.org" (nth (1+ (cl-position "--output" cmd :test #'equal)) cmd))))))
+
+(ert-deftest test-calendar-sync--api-command-normal-window-from-defvars ()
+  "Normal: past/future month flags reflect the configured defvars."
+  (let ((calendar-sync-python-command "python3")
+        (calendar-sync-past-months 6)
+        (calendar-sync-future-months 9)
+        (calendar-sync-skip-declined t))
+    (let ((cmd (calendar-sync--api-command "work" "primary" "/tmp/out.org")))
+      (should (equal "6" (nth (1+ (cl-position "--past-months" cmd :test #'equal)) cmd)))
+      (should (equal "9" (nth (1+ (cl-position "--future-months" cmd :test #'equal)) cmd))))))
+
+(ert-deftest test-calendar-sync--api-command-normal-honors-python-command ()
+  "Normal: a custom python command is used as argv[0]."
+  (let ((calendar-sync-python-command "/usr/bin/python3.14")
+        (calendar-sync-skip-declined t))
+    (let ((cmd (calendar-sync--api-command "work" "primary" "/tmp/out.org")))
+      (should (equal "/usr/bin/python3.14" (nth 0 cmd))))))
+
+;;; calendar-sync--api-command — Boundary (declined toggle)
+
+(ert-deftest test-calendar-sync--api-command-boundary-skip-declined-omits-flag ()
+  "Boundary: with skip-declined on (default), --keep-declined is absent.
+The helper filters declines by default, matching the .ics path."
+  (let ((calendar-sync-python-command "python3")
+        (calendar-sync-skip-declined t))
+    (let ((cmd (calendar-sync--api-command "work" "primary" "/tmp/out.org")))
+      (should-not (member "--keep-declined" cmd)))))
+
+(ert-deftest test-calendar-sync--api-command-boundary-keep-declined-adds-flag ()
+  "Boundary: with skip-declined nil, --keep-declined is passed through.
+This keeps the API path honoring the same toggle as the parser path."
+  (let ((calendar-sync-python-command "python3")
+        (calendar-sync-skip-declined nil))
+    (let ((cmd (calendar-sync--api-command "work" "primary" "/tmp/out.org")))
+      (should (member "--keep-declined" cmd)))))
+
+;;; calendar-sync--api-command — Error
+
+(ert-deftest test-calendar-sync--api-command-error-returns-string-list ()
+  "Error: every element of the command list is a string (make-process safe)."
+  (let ((calendar-sync-python-command "python3")
+        (calendar-sync-skip-declined nil))
+    (let ((cmd (calendar-sync--api-command "work" "primary" "/tmp/out.org")))
+      (should (cl-every #'stringp cmd)))))
+
+(provide 'test-calendar-sync--api-command)
+;;; test-calendar-sync--api-command.el ends here