Test: doc snippets must be compiled Examples

docs_test.go

@@ -0,0 +1,58 @@
+package mujica
+
+import (
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"testing"
+)
+
+var (
+	docsGoBlock = regexp.MustCompile("(?s)```go\n(.*?)```")
+	docsSpace   = regexp.MustCompile(`\s+`)
+)
+
+// TestDocSnippetsAreCompiledExamples keeps every doc's first Go block inside a compiled Example.
+func TestDocSnippetsAreCompiledExamples(t *testing.T) {
+	examples, err := filepath.Glob("example_*_test.go")
+	if err != nil {
+		t.Fatal(err)
+	}
+	var all strings.Builder
+	for _, f := range examples {
+		b, err := os.ReadFile(f)
+		if err != nil {
+			t.Fatal(err)
+		}
+		all.Write(b)
+	}
+	compiled := docsSpace.ReplaceAllString(all.String(), "")
+	docs, err := filepath.Glob("docs/components/*.md")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(docs) != 100 {
+		t.Fatalf("%d component docs, want 100", len(docs))
+	}
+	for _, d := range docs {
+		b, err := os.ReadFile(d)
+		if err != nil {
+			t.Fatal(err)
+		}
+		m := docsGoBlock.FindSubmatch(b)
+		if m == nil {
+			t.Errorf("%s has no Go example", d)
+			continue
+		}
+		for _, line := range strings.Split(string(m[1]), "\n") {
+			s := strings.TrimSpace(line)
+			if s == "" || strings.HasPrefix(s, "//") {
+				continue
+			}
+			if !strings.Contains(compiled, docsSpace.ReplaceAllString(s, "")) {
+				t.Errorf("%s: %q is not in any compiled Example", d, s)
+			}
+		}
+	}
+}