code blocks will be ignored, added unit test

Makefile

@@ -1,5 +1,11 @@
 all:
-	go run *.go tests/test.md
+	go run main.go tree.go test_files/test.md
+
+test:
+	go run main.go tree.go test_files/test.md
+	go run main.go tree.go test_files/README.md
+	go run main.go tree.go test_files/weird_headers.md
+	go run main.go tree.go test_files/audio.md
 
 clean:
 	rm -vf main

go.mod

@@ -0,0 +1,3 @@
+module mdtoc
+
+go 1.22.2

main.go

@@ -24,29 +24,38 @@ func is_heading(line string) bool {
 	}
 }
 
-func get_heading_level(heading_text string) int {
+func Get_heading_level(heading_text string) int {
 	level := 0
 	for i := 0; heading_text[i] == '#'; i++ {
 		level += 1
+		if i == (len(heading_text) - 1) {
+			break
+		}
 	}
 	return level
 }
 
 func parse_file(file_name string) []heading {
-	file_content_raw, err := os.ReadFile(file_name)
-
 	var headings []heading
 
+	file_content_raw, err := os.ReadFile(file_name)
+
 	if err != nil {
 		log.Fatal(err)
 	}
 
 	file_lines := strings.Split(string(file_content_raw), "\n")
 
+	is_codeblock := false
+
 	for index, value := range file_lines {
-		if is_heading(value) {
+		if strings.HasPrefix(value, "```") {
+			is_codeblock = !is_codeblock
+		}
+
+		if !is_codeblock && is_heading(value) {
 			headings = append(
-				headings, heading{value, get_heading_level(value), (index + 1)})
+				headings, heading{value, Get_heading_level(value), (index + 1)})
 		}
 	}
 	return headings

main_test.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"log"
+	"testing"
+)
+
+func TestGet_heading_level(t *testing.T) {
+	level := Get_heading_level("# foo")
+
+	if level < 0 || level > 6 {
+		log.Fatal("Level is not between 0 and 6.")
+	}
+
+	level = Get_heading_level("not a header")
+
+	if level != 0 {
+		log.Fatal("A non header should be level 0!")
+	}
+
+	level = Get_heading_level("#")
+
+	if level < 0 || level > 6 {
+		log.Fatal("Level is not between 0 and 6.")
+	}
+}