Merge pull request #113 from TAServers/74-diff-renderer

74 - Add diff renderer and improve reporting

packages/lest/CHANGELOG.md

@@ -14,6 +14,20 @@ The valid change types are:
 -   `Fixed` for any bug fixes.
 -   `Security` in case of vulnerabilities.
 
+## [3.1.0] - [#113](https://github.com/TAServers/lest/pull/113)
+
+### Added
+
+-   Added pretty diff rendering to `toEqual` matcher to show differences between deeply nested values
+
+### Changed
+
+-   `toBe` matcher now generates its message more in line with Jest to make comparing values easier
+-   All values displayed in test failure messages are now properly serialised to mostly valid Lua, including the contents of tables
+-   Test failure messages no longer include the expected and received values in the `expect(...).matcherName(...)` signature
+    -   This matches the behaviour of Jest and avoids duplicating information between the signature and failure message
+-   Test failure messages are no longer highlighted in red to give more control to matchers over how individual messages are formatted
+
 ## [3.0.0] - [#102](https://github.com/TAServers/lest/issues/102)
 
 ### Added

packages/lest/lest.config.lua

@@ -1,3 +1,5 @@
+package.path = "./src/lua/?.lua;./src/lua/?/index.lua;./?.lua"
+
 return {
 	testMatch = { "tests/lua/.+%.test%.lua", "src/lua/.+%.test%.lua" },
 }

packages/lest/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@taservers/lest",
-  "version": "3.0.0",
+  "version": "3.1.0",
   "license": "MIT",
   "description": "Painless Lua testing.",
   "homepage": "https://taservers.github.io/lest/",
@@ -16,10 +16,10 @@
     "lest": "./dist/bin/lest.js"
   },
   "scripts": {
-    "build:lua": "luabundler bundle src/lua/lest.lua -p \"./?.lua\" -o dist/lua/lest.lua",
+    "build:lua": "luabundler bundle src/lua/lest.lua -p \"./src/lua/?.lua\" -p \"./src/lua/?/index.lua\" -p \"./?.lua\" -o dist/lua/lest.lua",
     "build:ts": "tsc -p tsconfig.build.json",
     "build": "npm run build:lua && npm run build:ts",
-    "test:lua": "lua src/lua/lest.lua",
+    "test:lua": "npm run build:lua && lua dist/lua/lest.lua",
     "test:ts": "jest",
     "test": "npm run test:lua && npm run test:ts",
     "clean": "rimraf dist",

packages/lest/src/lua/asserts/matchers.lua

@@ -1,29 +1,32 @@
 --- Asserts the matcher passed.
 ---@param result lest.MatcherResult
 local function assertPass(result)
-	assert(result.pass, debug.traceback("Expected matcher to pass", 2))
+	if not result.pass then
+		error("Expected matcher to pass", 2)
+	end
 end
 
 --- Asserts the matcher failed.
 ---@param result lest.MatcherResult
 local function assertFail(result)
-	assert(not result.pass, debug.traceback("Expected matcher to fail", 2))
+	if result.pass then
+		error("Expected matcher to fail", 2)
+	end
 end
 
 --- Asserts the matcher returned the given message.
 ---@param result lest.MatcherResult
 local function assertMessage(result, message)
-	assert(
-		result.message == message,
-		debug.traceback(
+	if result.message ~= message then
+		error(
 			string.format(
 				"Expected message: %s\nReceived message: %s",
 				message,
 				result.message
 			),
 			2
 		)
-	)
+	end
 end
 
 return {

packages/lest/src/lua/asserts/type.lua

@@ -1,5 +1,5 @@
-local TypeError = require("src.lua.errors.type")
-local prettyValue = require("src.lua.utils.prettyValue")
+local TypeError = require("errors.type")
+local serialiseValue = require("utils.serialise-value")
 
 --- Asserts the object is of the specified type
 ---
@@ -9,7 +9,7 @@ local prettyValue = require("src.lua.utils.prettyValue")
 ---@param label? string
 ---@param level? number
 return function(object, typeStringOrMeta, label, level)
-	label = label or prettyValue(object)
+	label = label or serialiseValue(object)
 	level = (level or 1) + 1
 
 	if
@@ -34,7 +34,7 @@ return function(object, typeStringOrMeta, label, level)
 				string.format(
 					"Expected %s to be an instance of %s",
 					label,
-					prettyValue(typeStringOrMeta)
+					serialiseValue(typeStringOrMeta)
 				)
 			),
 			level

packages/lest/src/lua/errors/testresult.lua

@@ -1,16 +1,11 @@
-local COLOURS = require("src.lua.utils.consoleColours")
-local registerError = require("src.lua.errors.register")
+local registerError = require("errors.register")
 return registerError("TestResultError", function(message, signature)
 	return {
 		message = message,
 		signature = signature,
 	}
 end, {
 	__tostring = function(self)
-		return string.format(
-			"%s\n\n%s",
-			self.signature,
-			COLOURS.FAIL(self.message)
-		)
+		return string.format("%s\n\n%s", self.signature, self.message)
 	end,
 })

packages/lest/src/lua/expect.lua

@@ -1,30 +1,22 @@
-local COLOURS = require("src.lua.utils.consoleColours")
+local COLOURS = require("utils.consoleColours")
 
-local matchers = require("src.lua.matchers")
-local prettyValue = require("src.lua.utils.prettyValue")
-local TestResultError = require("src.lua.errors.testresult")
+local matchers = require("matchers")
+local TestResultError = require("errors.testresult")
 
 --- Builds a signature for the expect call
 ---@param name string -- Name of the matcher that was used
----@param args any -- Arguments passed to the matcher
----@param received any
 ---@param inverted boolean -- True if the condition was inverted
 ---@return string
-local function buildSignature(name, args, received, inverted)
-	local stringArgs = {}
-	for i, arg in ipairs(args) do
-		stringArgs[i] = prettyValue(arg)
-	end
-
+local function buildSignature(name, inverted)
 	return string.format(
 		"%s%s%s%s.%s%s%s%s",
 		COLOURS.DIMMED("expect("),
-		COLOURS.RECEIVED(prettyValue(received)),
+		COLOURS.RECEIVED("received"),
 		COLOURS.DIMMED(")"),
 		inverted and ".never" or "",
 		COLOURS.HIGHLIGHT(name),
 		COLOURS.DIMMED("("),
-		COLOURS.EXPECTED(table.concat(stringArgs, ", ")),
+		COLOURS.EXPECTED("expected"),
 		COLOURS.DIMMED(")")
 	)
 end
@@ -51,7 +43,7 @@ local function bindMatcher(name, matcher, received, inverted)
 			error(
 				TestResultError(
 					tostring(result.message),
-					buildSignature(name, { ... }, received, inverted)
+					buildSignature(name, inverted)
 				)
 			)
 		end

packages/lest/src/lua/matchers/equality.lua

@@ -1,16 +1,12 @@
-local prettyValue = require("src.lua.utils.prettyValue")
-local deepEqual = require("src.lua.utils.deepEqual")
+local serialiseValue = require("utils.serialise-value")
+local deepEqual = require("utils.deepEqual")
+local renderDiff = require("utils.render-diff")
 
 ---@type lest.Matcher
 local function toBe(ctx, received, expected)
 	return {
 		pass = received == expected,
-		message = string.format(
-			"Expected %s to%sbe %s",
-			prettyValue(received),
-			ctx.inverted and " not " or " ",
-			prettyValue(expected)
-		),
+		message = renderDiff(expected, received, false, ctx.inverted),
 	}
 end
 
@@ -20,7 +16,7 @@ local function toBeDefined(ctx, received)
 		pass = received ~= nil,
 		message = string.format(
 			"Expected %s to be %sdefined",
-			prettyValue(received),
+			serialiseValue(received),
 			ctx.inverted and "un" or ""
 		),
 	}
@@ -32,7 +28,7 @@ local function toBeUndefined(ctx, received)
 		pass = received == nil,
 		message = string.format(
 			"Expected %s to be %sdefined",
-			prettyValue(received),
+			serialiseValue(received),
 			ctx.inverted and "" or "un"
 		),
 	}
@@ -41,12 +37,7 @@ end
 local function toEqual(ctx, received, expected)
 	return {
 		pass = deepEqual(received, expected),
-		message = string.format(
-			"Expected %s to%sdeeply equal %s",
-			prettyValue(received),
-			ctx.inverted and " not " or " ",
-			prettyValue(expected)
-		),
+		message = renderDiff(expected, received, true, ctx.inverted),
 	}
 end
 
@@ -56,7 +47,7 @@ local function toBeTruthy(ctx, received)
 		pass = not not received,
 		message = string.format(
 			"Expected %s to%sbe truthy",
-			prettyValue(received),
+			serialiseValue(received),
 			ctx.inverted and " not " or " "
 		),
 	}
@@ -68,7 +59,7 @@ local function toBeFalsy(ctx, received)
 		pass = not received,
 		message = string.format(
 			"Expected %s to%sbe falsy",
-			prettyValue(received),
+			serialiseValue(received),
 			ctx.inverted and " not " or " "
 		),
 	}
@@ -82,9 +73,9 @@ local function toBeInstanceOf(ctx, received, metatable)
 		pass = getmetatable(received) == metatable,
 		message = string.format(
 			"Expected %s to%sbe an instance of %s",
-			prettyValue(received),
+			serialiseValue(received),
 			ctx.inverted and " not " or " ",
-			prettyValue(metatable)
+			serialiseValue(metatable)
 		),
 	}
 end