Calque (calque v1.6.0)

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Calque — a lightweight snapshot testing and review tool for Elixir projects.

Calque allows you to:

  • Record test outputs as snapshot files (*.snap)
  • Compare new outputs against previously accepted snapshots
  • Review and accept/reject snapshots interactively from the CLI

Typical usage

Calque.check(result, "my test title")

If no accepted snapshot exists, Calque will create one and fail the test, prompting you to review it with:

mix calque review

Calque stores all snapshots under calque_snapshots/ in your project root.

CLI commands

  • mix calque review — review new or changed snapshots interactively
  • mix calque accept-all — accept all pending snapshots
  • mix calque reject-all — reject all pending snapshots
  • mix calque clean — delete pending, rejected, and unreferenced snapshots
  • mix calque help — show CLI usage information

Summary

Types

cli_command()
snapshot()

Functions

check(content)

Performs a snapshot test using the calling function name as the snapshot title.

check(content, title)

Performs a snapshot test with an explicit snapshot title.

Types

cli_command()

@type cli_command() :: :review | :accept_all | :reject_all | :clean | :help

snapshot()

@type snapshot() :: Calque.Snapshot.t()

Functions

check(content)

(macro) 
@spec check(String.t()) :: :ok | no_return()

Performs a snapshot test using the calling function name as the snapshot title.

This macro is a convenience wrapper around check/2. The snapshot title is automatically inferred from the surrounding function or test name, making it the preferred API in most cases.

It behaves exactly like check/2: the content is compared against the accepted snapshot, and the test fails if a new snapshot is created or a difference is detected.

Examples

Inside an ExUnit test:

test "renders empty state" do
  html = render_empty_state()

  Calque.check(html)
end

The snapshot title will automatically be set to:

"renders empty state"

This keeps snapshot names stable and closely aligned with test intent, without requiring any manual naming.

check(content, title)

(macro) 
@spec check(String.t(), String.t()) :: :ok | no_return()

Performs a snapshot test with an explicit snapshot title.

This function writes the given content to a snapshot file (if none exists) and compares it against the previously accepted snapshot.

In practice, you will usually prefer check/1, which automatically derives the snapshot title from the calling test. Use check/2 when you need full control over the snapshot name.

Examples

Using an explicit snapshot title:

test "renders order confirmation" do
  html = render_confirmation(order)

  Calque.check(html, "order_confirmation")
end

If the snapshot matches the accepted version, the test passes silently:

:ok

If no snapshot exists yet, or if the content differs, the test fails and prints a helpful diff.