fix(nevermore-cli): tag only the script template as the batch test entry

tools/nevermore-cli/build-scripts/combine-test-places.luau

@@ -7,6 +7,11 @@
 --   1. Deserializes the .rbxl
 --   2. Reparents ServerScriptService children (the package root) into the combined ServerScriptService
 --   3. Reads the test script file and creates a Script under ReplicatedStorage._BatchScripts
+--
+-- The injected script is the ONLY thing tagged `_BatchTest_<slug>`, because that tag is how
+-- batch-test-runner picks what to execute and it can only execute one thing. This used to tag every
+-- Script under ServerScriptService instead, which is the same script right up until a project has
+-- two -- and then the runner ran whichever the tag happened to list first, silently testing nothing.
 
 local fs = require("@lune/fs")
 local process = require("@lune/process")
@@ -40,17 +45,33 @@ local baseContents = fs.readFile(packages[1].rbxlPath)
 local game = roblox.deserializePlace(baseContents)
 
 local HttpService = game:GetService("HttpService")
+local ReplicatedStorage = game:GetService("ReplicatedStorage")
 local ServerScriptService = game:GetService("ServerScriptService")
 
 ServerScriptService.LoadStringEnabled = true
 
--- Process first package
-for _, descendant in ServerScriptService:GetDescendants() do
-	if descendant:IsA("Script") then
-		descendant:AddTag("_BatchTest_" .. packages[1].slug)
+local batchScripts = roblox.Instance.new("Folder")
+batchScripts.Name = "_BatchScripts"
+batchScripts.Parent = ReplicatedStorage
+
+-- Carries the package's entry point as source for the runner to loadstring. Never runs on its own:
+-- a Script under ReplicatedStorage is inert, and the runner wants to choose when it runs anyway.
+local function injectTestScript(pkg)
+	if not fs.isFile(pkg.scriptPath) then
+		print(`[CombinePlaces] No script template for {pkg.slug} at {pkg.scriptPath}`)
+		process.exit(1)
 	end
+
+	local testScript = roblox.Instance.new("Script")
+	testScript.Name = pkg.slug
+	testScript.Source = fs.readFile(pkg.scriptPath)
+	testScript:AddTag("_BatchTest_" .. pkg.slug)
+	testScript.Parent = batchScripts
 end
 
+-- Process first package
+injectTestScript(packages[1])
+
 -- Process remaining packages: deserialize each and reparent ServerScriptService children.
 -- NOTE: ObjectValues (links) within each package's subtree are preserved when the
 -- whole subtree is reparented as a unit. This works because all ObjectValue targets
@@ -69,11 +90,7 @@ for idx = 2, #packages do
 		HttpService.HttpEnabled = true
 	end
 
-	for _, descendant in packageServerScriptService:GetDescendants() do
-		if descendant:IsA("Script") then
-			descendant:AddTag("_BatchTest_" .. pkg.slug)
-		end
-	end
+	injectTestScript(pkg)
 
 	-- Reparent all ServerScriptService children (non-recursively, just move the roots)
 	for _, child in packageServerScriptService:GetChildren() do

tools/nevermore-cli/templates/batch-test-runner.luau

@@ -16,7 +16,15 @@ local scriptSources = {}
 for _, slug in packageSlugs do
 	local tagged = CollectionService:GetTagged(`_BatchTest_{slug}`)
 	local inst = tagged[1]
-	if inst then
+	if #tagged > 1 then
+		-- Refused rather than picked. Running whichever one the tag listed first is how this fails
+		-- quietly: a script that returns without erroring reports as a pass having tested nothing.
+		local fullNames = {}
+		for _, taggedInstance in tagged do
+			table.insert(fullNames, taggedInstance:GetFullName())
+		end
+		warn(`[BatchTest] {slug}: {#tagged} instances tagged _BatchTest_{slug}: {table.concat(fullNames, ", ")}`)
+	elseif inst then
 		scriptSources[slug] = inst.Source
 	else
 		warn(`[BatchTest] Failed to find script source for {slug}`)
@@ -42,7 +50,7 @@ for _, slug in packageSlugs do
 	local scriptSource = scriptSources[slug]
 	if not scriptSource then
 		print("===BATCH_TEST_BEGIN " .. slug .. "===")
-		warn(`[BatchTest] {slug}: No test script found for {slug}. Is it tagged with _BatchTest_{slug}?`)
+		warn(`[BatchTest] {slug}: No test script to run. Is exactly one instance tagged _BatchTest_{slug}?`)
 		print("===BATCH_TEST_END " .. slug .. " FAIL 0===")
 		table.insert(results, { slug = slug, success = false, durationMs = 0, error = "No test script found" })
 		continue