From 3a40c818ef9ac27d89154c282b5e6b1cc99cb4c5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Luis=20Eduardo=20Jer=C3=A9z=20Gir=C3=B3n?=
 <eduardo.devop@gmail.com>
Date: Fri, 19 Jul 2024 23:13:55 -0600
Subject: [PATCH] Add string utility functions for file handling

---
 .../get_content_type_from_file_name.go        | 62 +++++++++++++++++++
 .../get_content_type_from_file_name_test.go   | 38 ++++++++++++
 internal/util/strutil/remove_leading_slash.go | 10 +++
 .../util/strutil/remove_leading_slash_test.go | 50 +++++++++++++++
 4 files changed, 160 insertions(+)
 create mode 100644 internal/util/strutil/get_content_type_from_file_name.go
 create mode 100644 internal/util/strutil/get_content_type_from_file_name_test.go
 create mode 100644 internal/util/strutil/remove_leading_slash.go
 create mode 100644 internal/util/strutil/remove_leading_slash_test.go

diff --git a/internal/util/strutil/get_content_type_from_file_name.go b/internal/util/strutil/get_content_type_from_file_name.go
new file mode 100644
index 0000000..197e1f0
--- /dev/null
+++ b/internal/util/strutil/get_content_type_from_file_name.go
@@ -0,0 +1,62 @@
+package strutil
+
+import "strings"
+
+// GetContentTypeFromFileName returns the content type
+// of a file based on its file extension from the name.
+//
+// If the file extension is not recognized, it returns
+// "application/octet-stream".
+func GetContentTypeFromFileName(fileName string) string {
+	fileName = strings.ToLower(fileName)
+
+	if strings.HasSuffix(fileName, ".pdf") {
+		return "application/pdf"
+	}
+
+	if strings.HasSuffix(fileName, ".png") {
+		return "image/png"
+	}
+
+	if strings.HasSuffix(fileName, ".jpg") || strings.HasSuffix(fileName, ".jpeg") {
+		return "image/jpeg"
+	}
+
+	if strings.HasSuffix(fileName, ".gif") {
+		return "image/gif"
+	}
+
+	if strings.HasSuffix(fileName, ".bmp") {
+		return "image/bmp"
+	}
+
+	if strings.HasSuffix(fileName, ".json") {
+		return "application/json"
+	}
+
+	if strings.HasSuffix(fileName, ".csv") {
+		return "text/csv"
+	}
+
+	if strings.HasSuffix(fileName, ".xml") {
+		return "application/xml"
+	}
+
+	if strings.HasSuffix(fileName, ".txt") {
+		return "text/plain"
+	}
+
+	if strings.HasSuffix(fileName, ".html") {
+		return "text/html"
+	}
+
+	if strings.HasSuffix(fileName, ".zip") {
+		return "application/zip"
+	}
+
+	if strings.HasSuffix(fileName, ".sql") {
+		return "application/sql"
+	}
+
+	return "application/octet-stream"
+}
diff --git a/internal/util/strutil/get_content_type_from_file_name_test.go b/internal/util/strutil/get_content_type_from_file_name_test.go
new file mode 100644
index 0000000..85d1ac1
--- /dev/null
+++ b/internal/util/strutil/get_content_type_from_file_name_test.go
@@ -0,0 +1,38 @@
+package strutil
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetContentTypeFromFileName(t *testing.T) {
+	tests := []struct {
+		fileName string
+		expected string
+	}{
+		{"documento.pdf", "application/pdf"},
+		{"imagen.png", "image/png"},
+		{"foto.jpg", "image/jpeg"},
+		{"foto.jpeg", "image/jpeg"},
+		{"animacion.gif", "image/gif"},
+		{"imagen.bmp", "image/bmp"},
+		{"datos.json", "application/json"},
+		{"tabla.csv", "text/csv"},
+		{"config.xml", "application/xml"},
+		{"nota.txt", "text/plain"},
+		{"pagina.html", "text/html"},
+		{"archivo.zip", "application/zip"},
+		{"archivo.sql", "application/sql"},
+		{"archivo.desconocido", "application/octet-stream"}, // unknown extension
+		{"MAYUSCULAS.JPG", "image/jpeg"},                    // upper case
+		{"MezclaDeMayusculasYMinusculas.PnG", "image/png"},  // mixed case
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.fileName, func(t *testing.T) {
+			result := GetContentTypeFromFileName(tt.fileName)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
diff --git a/internal/util/strutil/remove_leading_slash.go b/internal/util/strutil/remove_leading_slash.go
new file mode 100644
index 0000000..6afd97b
--- /dev/null
+++ b/internal/util/strutil/remove_leading_slash.go
@@ -0,0 +1,10 @@
+package strutil
+
+// RemoveLeadingSlash removes the leading slash from a string.
+func RemoveLeadingSlash(str string) string {
+	if len(str) > 0 && str[0] == '/' {
+		return str[1:]
+	}
+
+	return str
+}
diff --git a/internal/util/strutil/remove_leading_slash_test.go b/internal/util/strutil/remove_leading_slash_test.go
new file mode 100644
index 0000000..486c447
--- /dev/null
+++ b/internal/util/strutil/remove_leading_slash_test.go
@@ -0,0 +1,50 @@
+package strutil
+
+import "testing"
+
+func TestRemoveLeadingSlash(t *testing.T) {
+	tests := []struct {
+		name string
+		str  string
+		want string
+	}{
+		{
+			name: "Remove leading slash",
+			str:  "/test/",
+			want: "test/",
+		},
+		{
+			name: "Remove leading slash from empty string",
+			str:  "",
+			want: "",
+		},
+		{
+			name: "Remove leading slash from string without leading slash",
+			str:  "test/",
+			want: "test/",
+		},
+		{
+			name: "Remove leading slash from string with multiple leading slashes",
+			str:  "//test/",
+			want: "/test/",
+		},
+		{
+			name: "With special characters",
+			str:  "/test/!@#$%^&*()_+/",
+			want: "test/!@#$%^&*()_+/",
+		},
+		{
+			name: "With special characters (emojis)",
+			str:  "/test/!@#$%^&*()_+😀/",
+			want: "test/!@#$%^&*()_+😀/",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := RemoveLeadingSlash(tt.str); got != tt.want {
+				t.Errorf("RemoveLeadingSlash() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}