Add tests for QueryReporter

This commit is contained in:
Claudio Ortolina
2026-04-10 11:10:12 +01:00
parent 8826834549
commit fcf5adde2f
+279
View File
@@ -0,0 +1,279 @@
defmodule MusicLibrary.QueryReporterTest do
use ExUnit.Case, async: true
alias MusicLibrary.QueryReporter
@event [:music_library, :repo, :query]
setup do
path =
Path.join(
System.tmp_dir!(),
"query_reporter_test_#{System.unique_integer([:positive])}.sql"
)
on_exit(fn ->
QueryReporter.stop()
File.rm(path)
end)
%{path: path}
end
describe "start/1" do
test "creates the output file with a header", %{path: path} do
QueryReporter.start(path)
content = File.read!(path)
assert content =~ "-- Query Reporter started at"
end
test "truncates existing file on restart", %{path: path} do
File.write!(path, "old content\n")
QueryReporter.start(path)
content = File.read!(path)
refute content =~ "old content"
assert content =~ "-- Query Reporter started at"
end
test "attaches a telemetry handler", %{path: path} do
QueryReporter.start(path)
handlers = :telemetry.list_handlers(@event)
assert Enum.any?(handlers, &(&1.id == "music-library-query-reporter"))
end
test "restarts cleanly when already running", %{path: path} do
QueryReporter.start(path)
new_path = path <> ".new"
on_exit(fn -> File.rm(new_path) end)
QueryReporter.start(new_path)
assert File.exists?(new_path)
handlers = :telemetry.list_handlers(@event)
matching = Enum.filter(handlers, &(&1.id == "music-library-query-reporter"))
assert length(matching) == 1
end
end
describe "stop/0" do
test "detaches the telemetry handler", %{path: path} do
QueryReporter.start(path)
assert :ok = QueryReporter.stop()
handlers = :telemetry.list_handlers(@event)
refute Enum.any?(handlers, &(&1.id == "music-library-query-reporter"))
end
test "returns error when not running" do
assert {:error, "Query reporter is not running"} = QueryReporter.stop()
end
end
describe "handle_event/4" do
test "appends a formatted query entry to the file", %{path: path} do
QueryReporter.start(path)
metadata = %{
query: "SELECT * FROM records WHERE id = ?",
cast_params: [1],
params: [1],
stacktrace: []
}
measurements = %{total_time: 1_000_000, query_time: 800_000}
QueryReporter.handle_event(@event, measurements, metadata, path)
content = File.read!(path)
assert content =~ "SELECT * FROM records WHERE id = 1;"
end
test "writes timing metadata", %{path: path} do
QueryReporter.start(path)
metadata = %{query: "SELECT 1", cast_params: [], params: [], stacktrace: []}
measurements = %{total_time: 2_000_000, query_time: 1_500_000, queue_time: 300_000}
QueryReporter.handle_event(@event, measurements, metadata, path)
content = File.read!(path)
assert content =~ "-- total="
assert content =~ "db="
assert content =~ "queue="
end
test "omits missing timing keys", %{path: path} do
QueryReporter.start(path)
metadata = %{query: "SELECT 1", cast_params: [], params: [], stacktrace: []}
measurements = %{total_time: 1_000_000}
QueryReporter.handle_event(@event, measurements, metadata, path)
content = File.read!(path)
assert content =~ "total="
refute content =~ "db="
refute content =~ "queue="
refute content =~ "decode="
end
@tag :capture_log
test "logs a warning and does not raise on write failure" do
metadata = %{query: "SELECT 1", cast_params: [], params: [], stacktrace: []}
measurements = %{total_time: 1_000_000}
QueryReporter.handle_event(@event, measurements, metadata, "/nonexistent/dir/file.sql")
end
end
describe "query interpolation" do
test "interpolates integer params", %{path: path} do
QueryReporter.start(path)
emit_query(path, "SELECT * FROM records WHERE id = ?", [42])
assert File.read!(path) =~ "WHERE id = 42;"
end
test "interpolates float params", %{path: path} do
QueryReporter.start(path)
emit_query(path, "SELECT * FROM records WHERE score > ?", [3.14])
assert File.read!(path) =~ "WHERE score > 3.14;"
end
test "interpolates nil as NULL", %{path: path} do
QueryReporter.start(path)
emit_query(path, "SELECT * FROM records WHERE deleted_at = ?", [nil])
assert File.read!(path) =~ "WHERE deleted_at = NULL;"
end
test "interpolates boolean true as 1", %{path: path} do
QueryReporter.start(path)
emit_query(path, "SELECT * FROM records WHERE active = ?", [true])
assert File.read!(path) =~ "WHERE active = 1;"
end
test "interpolates boolean false as 0", %{path: path} do
QueryReporter.start(path)
emit_query(path, "SELECT * FROM records WHERE active = ?", [false])
assert File.read!(path) =~ "WHERE active = 0;"
end
test "interpolates string params with single-quote escaping", %{path: path} do
QueryReporter.start(path)
emit_query(path, "SELECT * FROM records WHERE title = ?", ["Rock'n'Roll"])
assert File.read!(path) =~ "WHERE title = 'Rock''n''Roll';"
end
test "interpolates binary data as hex", %{path: path} do
QueryReporter.start(path)
emit_query(path, "SELECT * FROM records WHERE hash = ?", [<<0xDE, 0xAD, 0xBE, 0xEF>>])
assert File.read!(path) =~ "WHERE hash = X'DEADBEEF';"
end
test "interpolates multiple params", %{path: path} do
QueryReporter.start(path)
emit_query(path, "INSERT INTO records (title, year) VALUES (?, ?)", ["Album", 2024])
content = File.read!(path)
assert content =~ "VALUES ('Album', 2024);"
end
test "leaves query unchanged when params list is empty", %{path: path} do
QueryReporter.start(path)
emit_query(path, "SELECT count(*) FROM records", [])
assert File.read!(path) =~ "SELECT count(*) FROM records;"
end
test "uses cast_params over params when both present", %{path: path} do
QueryReporter.start(path)
metadata = %{
query: "SELECT * FROM records WHERE id = ?",
cast_params: [99],
params: [1],
stacktrace: []
}
QueryReporter.handle_event(@event, %{total_time: 1_000_000}, metadata, path)
assert File.read!(path) =~ "WHERE id = 99;"
end
test "falls back to params when cast_params is nil", %{path: path} do
QueryReporter.start(path)
metadata = %{
query: "SELECT * FROM records WHERE id = ?",
cast_params: nil,
params: [7],
stacktrace: []
}
QueryReporter.handle_event(@event, %{total_time: 1_000_000}, metadata, path)
assert File.read!(path) =~ "WHERE id = 7;"
end
end
describe "source location" do
test "includes source location from stacktrace", %{path: path} do
QueryReporter.start(path)
stacktrace = [{__MODULE__, :test_function, 2, [file: ~c"test/my_test.exs", line: 42]}]
metadata = %{query: "SELECT 1", cast_params: [], params: [], stacktrace: stacktrace}
QueryReporter.handle_event(@event, %{total_time: 1_000_000}, metadata, path)
content = File.read!(path)
assert content =~ "-- MusicLibrary.QueryReporterTest.test_function/2"
assert content =~ "test/my_test.exs:42"
end
test "omits location comment when stacktrace is nil", %{path: path} do
QueryReporter.start(path)
metadata = %{query: "SELECT 1", cast_params: [], params: [], stacktrace: nil}
QueryReporter.handle_event(@event, %{total_time: 1_000_000}, metadata, path)
content = File.read!(path)
lines = content |> String.split("\n") |> Enum.reject(&(&1 == ""))
# Should only have the header, timing, and query — no location line
refute Enum.any?(lines, &String.contains?(&1, "at:"))
end
test "omits location comment when stacktrace is empty", %{path: path} do
QueryReporter.start(path)
metadata = %{query: "SELECT 1", cast_params: [], params: [], stacktrace: []}
QueryReporter.handle_event(@event, %{total_time: 1_000_000}, metadata, path)
content = File.read!(path)
lines = content |> String.split("\n") |> Enum.reject(&(&1 == ""))
refute Enum.any?(lines, &String.contains?(&1, "at:"))
end
end
defp emit_query(path, query, params) do
metadata = %{query: query, cast_params: params, params: params, stacktrace: []}
measurements = %{total_time: 1_000_000}
QueryReporter.handle_event(@event, measurements, metadata, path)
end
end