Add some integration tests for the CLI

Cargo.toml

@@ -54,3 +54,7 @@ mbedtls-sys-auto = { git = "https://github.com/mobilecoinfoundation/rust-mbedtls
 
 # Override lmdb-rkv for a necessary bugfix (see https://github.com/mozilla/lmdb-rs/pull/80)
 lmdb-rkv = { git = "https://github.com/mozilla/lmdb-rs", rev = "df1c2f5" }
+
+[dev-dependencies]
+assert_cmd = "2.0"
+predicates = "2.1.5"

tests/cli.rs

@@ -0,0 +1,19 @@
+use assert_cmd::Command;
+use predicates::prelude::*;
+
+#[test]
+fn minimal_args() -> Result<(), Box<dyn std::error::Error>> {
+    let mut cmd = Command::cargo_bin("mc-crawler")?;
+    cmd.assert().success();
+    Ok(())
+}
+
+#[test]
+fn invalid_bootstrap_file_passed() -> Result<(), Box<dyn std::error::Error>> {
+    let mut cmd = Command::cargo_bin("mc-crawler")?;
+    cmd.arg("./invalid-file");
+    cmd.assert()
+        .failure()
+        .stderr(predicate::str::contains("Error opening bootstrap file"));
+    Ok(())
+}