From 0aa85dd219f4be8dbf3383661fd2b42370945b87 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Sun, 21 Jun 2026 03:19:08 -0400 Subject: test: make subr mocks variadic for native-comp, add arity meta-test Re-enabling native-comp surfaced a suite-wide fragility. When a test redefines a C primitive (or a native-compiled function), native-comp routes native callers through a trampoline that calls the mock with the primitive's maximum arity. A fixed-arity mock narrower than the primitive then throws wrong-number-of-arguments, intermittently, as the eln-cache fills. I swept every arity-narrow subr mock to append &rest _ (188 sites, preserving any named args the body uses), and added tests/test-meta-subr-mock-arity.el, which fails make test on any subr mock too narrow for the primitive's arity. The rule isn't "never mock a subr". The suite mocks message and completing-read freely. It's "a subr mock must accept the primitive's arity." Background, the three failure modes, and the research are in docs/native-comp-subr-mocking.org. --- tests/test-prog-json--json-format-buffer.el | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'tests/test-prog-json--json-format-buffer.el') diff --git a/tests/test-prog-json--json-format-buffer.el b/tests/test-prog-json--json-format-buffer.el index 70d7e98bb..c6297a404 100644 --- a/tests/test-prog-json--json-format-buffer.el +++ b/tests/test-prog-json--json-format-buffer.el @@ -16,7 +16,7 @@ (ert-deftest test-prog-json--json-format-buffer-invokes-jq-argv () "Normal: with jq present, the formatter calls jq via argv, no shell." (let (program args) - (cl-letf (((symbol-function 'executable-find) (lambda (_p) "/usr/bin/jq")) + (cl-letf (((symbol-function 'executable-find) (lambda (_p &rest _) "/usr/bin/jq")) ((symbol-function 'call-process-region) (lambda (_start _end prog &rest rest) (setq program prog @@ -31,7 +31,7 @@ (ert-deftest test-prog-json--json-format-buffer-no-clobber-on-failure () "Error: a non-zero jq exit leaves the buffer untouched and signals an error." - (cl-letf (((symbol-function 'executable-find) (lambda (_p) "/usr/bin/jq")) + (cl-letf (((symbol-function 'executable-find) (lambda (_p &rest _) "/usr/bin/jq")) ((symbol-function 'call-process-region) (lambda (_start _end _prog _delete buffer &rest _) (with-current-buffer buffer (insert "jq: parse error")) @@ -112,7 +112,7 @@ (ert-deftest test-prog-json--json-format-buffer-fallback-formats-without-jq () "Falls back to built-in formatter when jq is not found." - (cl-letf (((symbol-function 'executable-find) (lambda (_) nil))) + (cl-letf (((symbol-function 'executable-find) (lambda (_ &rest _) nil))) (with-temp-buffer (insert "{\"b\":1,\"a\":2}") (cj/json-format-buffer) -- cgit v1.2.3