Lua: add module `pandoc.json` to handle JSON encoding

Closes: #8605

1 files changed, 101 insertions, 0 deletions

diff --git a/pandoc-lua-engine/test/lua/module/pandoc-json.lua b/pandoc-lua-engine/test/lua/module/pandoc-json.lua
new file mode 100644
index 000000000..c2d4f86d4
--- /dev/null
+++ b/pandoc-lua-engine/test/lua/module/pandoc-json.lua
@@ -0,0 +1,101 @@
+--
+-- Tests for the system module
+--
+local json = require 'pandoc.json'
+local tasty = require 'tasty'
+
+local group = tasty.test_group
+local test = tasty.test_case
+local assert = tasty.assert
+
+return {
+  -- Check existence of static fields
+  group 'static fields' {
+    test('null', function ()
+      assert.are_equal(type(json.null), 'userdata')
+    end),
+  },
+
+  group 'encode' {
+    test('string', function ()
+      assert.are_equal(json.encode 'one\ntwo', '"one\\ntwo"')
+    end),
+    test('null', function ()
+      assert.are_equal(json.encode(json.null), 'null')
+    end),
+    test('number', function ()
+      assert.are_equal(json.encode(42), '42')
+    end),
+    test('object', function ()
+      assert.are_same(json.encode{a = 5}, '{"a":5}')
+    end),
+    test('object with metamethod', function ()
+      local obj = setmetatable(
+        {title = 23},
+        {
+          __tojson = function (obj)
+            return '"Nichts ist so wie es scheint"'
+          end
+        }
+      )
+      assert.are_same(json.encode(obj), [["Nichts ist so wie es scheint"]])
+    end),
+    test('Inline (Space)', function ()
+      assert.are_equal(
+        json.encode(pandoc.Space()),
+        '{"t":"Space"}'
+      )
+    end),
+    test('Block (HorizontalRule)', function ()
+      assert.are_equal(
+        json.encode(pandoc.HorizontalRule()),
+        '{"t":"HorizontalRule"}'
+      )
+    end),
+    test('Inlines list', function ()
+      assert.are_equal(
+        json.encode(pandoc.Inlines{pandoc.Space()}),
+        '[{"t":"Space"}]'
+      )
+    end),
+    test('Pandoc', function ()
+      assert.are_equal(
+        type(json.encode(pandoc.Pandoc{'Hello from Lua!'})),
+        'string'
+      )
+    end),
+  },
+
+  group 'decode' {
+    test('string', function ()
+      assert.are_equal(json.decode '"one\\ntwo"', 'one\ntwo')
+    end),
+    test('null', function ()
+      assert.are_equal(json.decode 'null', json.null)
+    end),
+    test('number', function ()
+      assert.are_equal(json.decode '42', 42)
+    end),
+    test('object', function ()
+      assert.are_same(json.decode '{"a":5}', {a = 5})
+    end),
+    test('Inline (Space)', function ()
+      assert.are_equal(json.decode '{"t":"Space"}', pandoc.Space())
+    end),
+    test('Inline (Str)', function ()
+      assert.are_equal(json.decode '{"t":"Str", "c":"a"}', pandoc.Str 'a')
+    end),
+    test('disabled AST check', function ()
+      assert.are_same(
+        json.decode('{"t":"Str", "c":"a"}', false),
+        {t = 'Str', c = 'a'}
+      )
+    end),
+    test('Inlines list', function ()
+      assert.are_equal(
+        json.decode '[{"t":"Space"}]',
+        pandoc.Inlines{pandoc.Space()}
+      )
+    end)
+  },
+}