test(repr): add tests

Author: haithium

spec/repr_spec.lua

@@ -0,0 +1,101 @@
+local mods = require("mods")
+
+local repr = mods.repr
+local fmt = string.format
+
+describe("mods.repr", function()
+  local fn = function() end
+  local co = coroutine.create(fn)
+  local keywords = mods.keyword.kwlist()
+
+  -- stylua: ignore
+  local tests = {
+    ---------input--------|---------------------expected---------------------
+    { nil                 , "nil"                                           },
+    { true                , "true"                                          },
+    { false               , "false"                                         },
+    { 42                  , "42"                                            },
+    { 'He said "hi"'      , [['He said "hi"']]                              },
+    { { hello = "world" } , '{\n  hello = "world"\n}'                       },
+    { { "a", "b", "c" }   , '{\n  [1] = "a",\n  [2] = "b",\n  [3] = "c"\n}' },
+    { {}                  , '{}'                                            },
+    { { { {} } }          , '{\n  [1] = {\n    [1] = {}\n  }\n}'            },
+    { fn                  , tostring(fn)                                    },
+    { co                  , tostring(co)                                    },
+  }
+
+  for i = 1, #tests do
+    local input, expected = unpack(tests[i], 1, 2)
+    it(fmt("repr (%s)", inspect(input)), function()
+      local res = repr(input)
+      assert.are.equal(expected, res)
+    end)
+  end
+
+  for _, v in ipairs(keywords) do
+    it(fmt("repr(%q) brackets reserved keys", v), function()
+      local expected = '{\n  ["' .. v .. '"] = true\n}'
+      assert.are_equal(expected, repr({ [v] = true }))
+    end)
+  end
+
+  it("renders complex nested tables with shared refs and cycles", function()
+    local root = { title = "root" }
+    local child = { name = "child" }
+    local leaf = { value = 99 }
+    root.child = child
+    root.self = root
+    root.shared_a = leaf
+    root.shared_b = leaf
+    root.list = { child, { back = root } }
+    child.parent = root
+    child.link = leaf
+    leaf.owner = child
+
+    local expected = [[
+{
+  child = {
+    link = {
+      owner = <cycle>,
+      value = 99
+    },
+    name = "child",
+    parent = <cycle>
+  },
+  list = {
+    [1] = {
+      link = {
+        owner = <cycle>,
+        value = 99
+      },
+      name = "child",
+      parent = <cycle>
+    },
+    [2] = {
+      back = <cycle>
+    }
+  },
+  self = <cycle>,
+  shared_a = {
+    owner = {
+      link = <cycle>,
+      name = "child",
+      parent = <cycle>
+    },
+    value = 99
+  },
+  shared_b = {
+    owner = {
+      link = <cycle>,
+      name = "child",
+      parent = <cycle>
+    },
+    value = 99
+  },
+  title = "root"
+}]]
+
+    local res = repr(root)
+    assert.are_equal(expected, res)
+  end)
+end)