README for first build

Makefile

@@ -23,6 +23,7 @@
 #
 # Usage:
 #   make            # typecheck and bundle into build/
+#   make test       # run the unit tests
 #   make dist       # build, then zip build/ into logsdu-<version>.zip
 #   make clean      # remove build/ and the zip
 #
@@ -36,10 +37,16 @@ EXT_ID := logsdu
 VERSION := $(shell node -p "require('./package.json').version")
 DIST := $(EXT_ID)-$(VERSION).zip
 
-.PHONY: all build dist clean check-deps
+.PHONY: all build test dist clean check-deps
 
 all: build
 
+# Unit tests for the pure logic: the input formatters and the decision that
+# says whether a page load may press "Entrar". Run straight through Node's
+# built-in runner and type stripping, so there is no test framework to install.
+test:
+	node --test "src/**/*.test.ts"
+
 # Call the local toolchain directly, so this works regardless of how pnpm is
 # provided (corepack vs standalone). Run "corepack pnpm install" first.
 build: check-deps