Share test assertion helpers

1 files changed, 40 insertions, 0 deletions

diff --git a/tests/assertions.lua b/tests/assertions.lua
new file mode 100644
index 0000000..fb97be0
--- /dev/null
+++ b/tests/assertions.lua
@@ -0,0 +1,40 @@
+local M = {}
+
+function M.same(expected, actual, message)
+  if expected ~= actual then
+    error((message or "values differ")
+      .. ": expected " .. tostring(expected)
+      .. ", got " .. tostring(actual), 2)
+  end
+end
+
+function M.truthy(value, message)
+  if not value then
+    error(message or "value must be true", 2)
+  end
+end
+
+function M.falsy(value, message)
+  if value then
+    error(message or "value must be false", 2)
+  end
+end
+
+function M.fails(body, expected_text)
+  local ok, failure = pcall(body)
+  if ok then
+    error("operation must fail", 2)
+  end
+  if expected_text and not tostring(failure):find(expected_text, 1, true) then
+    error("failure does not contain '" .. expected_text .. "': " .. tostring(failure), 2)
+  end
+end
+
+function M.list_same(expected, actual)
+  M.same(#expected, #actual, "list lengths differ")
+  for index = 1, #expected do
+    M.same(expected[index], actual[index], "list item " .. tostring(index) .. " differs")
+  end
+end
+
+return M