branch: elpa/buttercup
commit fc19598e89805975596c055fd9bed81ef9d1ff1c
Author: Ryan C. Thompson <r...@thompsonclan.org>
Commit: Ryan C. Thompson <r...@thompsonclan.org>
Add examples for checking return value and thrown signal of a spy
---
docs/writing-tests.md | 25 ++++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/docs/writing-tests.md b/docs/writing-tests.md
index cb72b28..643303c 100644
--- a/docs/writing-tests.md
+++ b/docs/writing-tests.md
@@ -524,7 +524,8 @@ will `signal` the specified value as an error.
### Other tracking properties
Every call to a spy is tracked and exposed using the `spy-calls`
-accessor.
+accessor. This tracks both successful calls and calls that throw
+errors.
`spy-calls-any` returns `nil` if the spy has not been called at all,
and then `t` once at least one call happens. `spy-calls-count` returns
@@ -536,6 +537,10 @@ current buffer and arguments passed to all calls.
the most recent call. `spy-calls-first` returns the current buffer and
arguments for the first call.
+The spy context structs returned by these functions have 4 slots:
+`args`, `return-value`, `thrown-signal`, and `current-buffer`. See
+below for examples accessing these.
+
Finally, `spy-calls-reset` clears all tracking for a spy.
```Emacs-Lisp
@@ -619,6 +624,24 @@ Finally, `spy-calls-reset` clears all tracking for a spy.
:args '(123)
:return-value nil)))
+ (it "tracks the return values and error signals of each call"
+ ;; Set up `set-foo' so that it can either return a value or throw
+ ;; an error
+ (spy-on 'set-foo :and-call-fake
+ (lambda (val &rest ignored)
+ (if (>= val 0)
+ val
+ (error "Value must not be negative"))))
+ (expect (set-foo 1) :to-be 1)
+ (expect (set-foo -1) :to-throw 'error)
+ (expect
+ (spy-context-return-value (spy-calls-first 'set-foo))
+ :to-be 1)
+ (expect
+ (spy-context-thrown-signal
+ (spy-calls-most-recent 'set-foo))
+ :to-equal (list 'error "Value must not be negative")))
+
(it "can be reset"
(set-foo 123)
(set-foo 456 "baz")
