assert: add Panics, PanicsWith

I want to use this for test coverage in microprom.

This turned out to be a bigger change than expected because testcapture
has a dependency on assert, which I had to invert to be able to use
testcapture.Capture() in assert.

1 files changed, 35 insertions, 0 deletions

diff --git a/assert/panic_test.go b/assert/panic_test.go
new file mode 100644
index 0000000..135ce18
--- /dev/null
+++ b/assert/panic_test.go
@@ -0,0 +1,35 @@
+// SPDX-FileCopyrightText: 2026 Stefan Majewsky <majewsky@gmx.net>
+// SPDX-License-Identifier: Apache-2.0
+
+package assert_test
+
+import (
+	"testing"
+
+	"go.xyrillian.de/gg/assert"
+	"go.xyrillian.de/gg/testcapture"
+)
+
+func TestPanics(t *testing.T) {
+	//only testing error cases here, coverage of the happy path is provided by
+	//usage of assert.Panics() in actual tests of other packages
+	tc := testcapture.Capture(t.Context(), t.Name(), func(t assert.TestingTB) {
+		assert.Panics(t, func() {
+			// no panic
+		})
+	})
+	assert.Equal(t, tc.Outcome, testcapture.OutcomeFailed)
+	assert.Equal(t, tc.Messages, []testcapture.Message{
+		testcapture.Log("did not panic"),
+	})
+
+	tc = testcapture.Capture(t.Context(), t.Name(), func(t assert.TestingTB) {
+		assert.PanicsWith[string](t, func() {
+			panic(42)
+		})
+	})
+	assert.Equal(t, tc.Outcome, testcapture.OutcomeFailed)
+	assert.Equal(t, tc.Messages, []testcapture.Message{
+		testcapture.Log("panicked with incorrect type: expected string, but got 42"),
+	})
+}