Add comprehensive integration tests (#40)

Fixes #10

Author: dotandev

tests/integration_tests.rs

@@ -67,3 +67,97 @@ ports:
         .success()
         .stdout(predicate::str::contains("Port 9999 is available"));
 }
+
+#[test]
+fn test_cli_init() {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let config_path = temp_dir.path().join(".envcheck.yaml");
+    
+    let mut cmd = Command::cargo_bin("envcheck").unwrap();
+    cmd.current_dir(temp_dir.path()).arg("init");
+    cmd.assert().success();
+    
+    assert!(config_path.exists());
+    let content = std::fs::read_to_string(config_path).unwrap();
+    assert!(content.contains("version: \"1\""));
+    assert!(content.contains("tools:"));
+}
+
+#[test]
+fn test_cli_json_output() {
+    let mut file = NamedTempFile::new().unwrap();
+    writeln!(
+        file,
+        r#"version: "1"
+env_vars:
+  - name: PATH
+    required: true
+"#
+    ).unwrap();
+
+    let mut cmd = Command::cargo_bin("envcheck").unwrap();
+    cmd.arg("--config").arg(file.path()).arg("--json");
+    
+    let output = cmd.assert().success().get_output().stdout.clone();
+    let stdout_str = String::from_utf8(output).unwrap();
+    
+    // Check if it's valid JSON and has expected fields
+    let v: serde_json::Value = serde_json::from_str(&stdout_str).unwrap();
+    assert!(v["results"].is_array());
+    assert!(v["summary"].is_object());
+    assert!(v["passed"].is_boolean());
+}
+
+#[test]
+fn test_cli_env_regex() {
+    let mut file = NamedTempFile::new().unwrap();
+    writeln!(
+        file,
+        r#"version: "1"
+env_vars:
+  - name: TEST_REGEX_VAR
+    pattern: "^[0-9]{{3}}$"
+    required: true
+"#
+    ).unwrap();
+
+    // Test failure
+    let mut cmd = Command::cargo_bin("envcheck").unwrap();
+    cmd.arg("--config").arg(file.path())
+       .env("TEST_REGEX_VAR", "abc");
+    cmd.assert()
+        .failure()
+        .stdout(predicate::str::contains("TEST_REGEX_VAR is set but does not match pattern"));
+
+    // Test success
+    let mut cmd = Command::cargo_bin("envcheck").unwrap();
+    cmd.arg("--config").arg(file.path())
+       .env("TEST_REGEX_VAR", "123");
+    cmd.assert()
+        .success()
+        .stdout(predicate::str::contains("TEST_REGEX_VAR is set and matches pattern"));
+}
+
+#[test]
+fn test_cli_directory_check() {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let dir_path = temp_dir.path().to_str().unwrap();
+    
+    let mut file = NamedTempFile::new().unwrap();
+    writeln!(
+        file,
+        r#"version: "1"
+files:
+  - path: "{}"
+    is_directory: true
+    required: true
+"#,
+        dir_path
+    ).unwrap();
+
+    let mut cmd = Command::cargo_bin("envcheck").unwrap();
+    cmd.arg("--config").arg(file.path());
+    cmd.assert()
+        .success()
+        .stdout(predicate::str::contains(format!("Directory {} exists", dir_path)));
+}