diff --git a/repl/lib_fileio.c b/repl/lib_fileio.c
index 8cfcfc4..f207fe1 100644
--- a/repl/lib_fileio.c
+++ b/repl/lib_fileio.c
@@ -232,8 +232,8 @@ static int nativeRead(Toy_Interpreter* interpreter, Toy_LiteralArray* arguments)
 		case TOY_LITERAL_STRING:
 		{
 			char value[TOY_MAX_STRING_LENGTH] = {0};
-			fread(value, sizeof(char), sizeof(value) - 1, file->fp);
-			value[TOY_MAX_STRING_LENGTH] = '\0';
+			fread(value, sizeof(char), TOY_MAX_STRING_LENGTH - 1, file->fp);
+			value[TOY_MAX_STRING_LENGTH - 1] = '\0';
 
 			resultLiteral = TOY_TO_STRING_LITERAL(Toy_createRefString(value));
 
diff --git a/test/scripts/lib/file/inputs.txt b/test/scripts/lib/file/inputs.txt
new file mode 100644
index 0000000..e8dba50
--- /dev/null
+++ b/test/scripts/lib/file/inputs.txt
@@ -0,0 +1,3 @@
+8
+12.5
+test
diff --git a/test/scripts/lib/file/outputs.txt b/test/scripts/lib/file/outputs.txt
new file mode 100644
index 0000000..8b2a4c9
--- /dev/null
+++ b/test/scripts/lib/file/outputs.txt
@@ -0,0 +1,2 @@
+8
+12.500000
\ No newline at end of file
diff --git a/test/scripts/lib/fileio.toy b/test/scripts/lib/fileio.toy
index 33ed34c..925f1e5 100644
--- a/test/scripts/lib/fileio.toy
+++ b/test/scripts/lib/fileio.toy
@@ -19,25 +19,27 @@ fn reset() {
 
 // test read
 {
-    // // enter test
-    // assert input.read(string) == "test\n", "read string failed";
+    var reader = open("scripts:/lib/file/inputs.txt", "r");
 
-    // // enter 8
-    // assert input.read(int) == 8, "read int failed";
+    assert reader.read(int) == 8, "read int failed";
+    assert reader.read(float) == 12.5, "read float failed";
+    assert reader.read(string) == "\ntest\n", "read string failed";
 
-    // // enter 12.5
-    // assert input.read(float) == 12.5, "read float failed";
+    // invaild types
+    assert input.read(type) == null, "read type failed";
+    assert input.read(any) == null, "read any failed";
 
-    // // invaild types
-    // assert input.read(type) == null, "read type failed";
-    // assert input.read(any) == null, "read any failed";
+    reader.close();
 }
 
 // test write
 {
-    assert output.write(8) == true, "write int failed";
-    assert output.write("\n") == true, "write string failed";
-    assert output.write(12.5) == true, "write float failed";
+    var writer = open("scripts:/lib/file/outputs.txt", "w");
+    assert writer.write(8) == true, "write int failed";
+    assert writer.write("\n") == true, "write string failed";
+    assert writer.write(12.5) == true, "write float failed";
+
+    writer.close();
 }