Lua: add a `pandoc.log` module.

1 files changed, 75 insertions, 0 deletions

diff --git a/pandoc-lua-engine/test/lua/module/pandoc-log.lua b/pandoc-lua-engine/test/lua/module/pandoc-log.lua
new file mode 100644
index 000000000..923f03cd9
--- /dev/null
+++ b/pandoc-lua-engine/test/lua/module/pandoc-log.lua
@@ -0,0 +1,75 @@
+--
+-- Tests for the pandoc.log module
+--
+-- =========================================
+-- PLEASE BE CAREFUL WHEN UPDATING THE TESTS
+-- =========================================
+--
+-- Some tests here are very, very fragile, as their correctness depends on the
+-- correct line number in this file.
+local log = require 'pandoc.log'
+local json = require 'pandoc.json'
+local tasty = require 'tasty'
+
+local group = tasty.test_group
+local test = tasty.test_case
+local assert = tasty.assert
+
+return {
+  group 'info' {
+    test('is a function', function ()
+           assert.are_equal(type(log.info), 'function')
+    end),
+    test('reports a warning', function ()
+      log.info('info test')
+      local msg = json.decode(json.encode(PANDOC_STATE.log[1]))
+      assert.are_equal(msg.message, 'info test')
+      assert.are_equal(msg.type, 'ScriptingInfo')
+    end),
+    test('info includes the correct number', function ()
+      log.info('line number test')
+      local msg = json.decode(json.encode(PANDOC_STATE.log[1]))
+      -- THIS NEEDS UPDATING if lines above are shifted.
+      assert.are_equal(msg.line, 30)
+    end),
+  },
+
+  group 'warn' {
+    test('is a function', function ()
+      assert.are_equal(type(log.warn), 'function')
+    end),
+    test('reports a warning', function ()
+      log.warn('testing')
+      local msg = json.decode(json.encode(PANDOC_STATE.log[1]))
+      assert.are_equal(msg.message, 'testing')
+      assert.are_equal(msg.type, 'ScriptingWarning')
+    end),
+  },
+
+  group 'silence' {
+    test('prevents info from being logged', function ()
+      local current_messages = PANDOC_STATE.log
+      log.silence(log.info, 'Just so you know')
+      assert.are_same(#current_messages, #PANDOC_STATE.log)
+      for i = 1, #current_messages do
+        assert.are_equal(
+          json.encode(current_messages[i]),
+          json.encode(PANDOC_STATE.log[i])
+        )
+      end
+    end),
+    test('returns the messages raised by the called function', function ()
+           local msgs = log.silence(log.info, 'Just so you know')
+           local msg = json.decode(json.encode(msgs[1]))
+           assert.are_equal(msg.message, 'Just so you know')
+    end),
+    test('returns function application results as additional return values',
+         function ()
+           local l, x, y = log.silence(function (a, b) return b, a + b end, 5, 8)
+           assert.are_same(l, {})
+           assert.are_equal(x, 8)
+        assert.are_equal(y, 13)
+      end
+    )
+  }
+}