Add test for empty dep table error

Signed-off-by: hi-rustin <rustin.liu@gmail.com>

tests/testsuite/cargo_add/add-basic.in/Cargo.toml

@@ -3,3 +3,6 @@
 [package]
 name = "cargo-list-test-fixture"
 version = "0.0.0"
+
+[dependencies]
+your-face = { }

tests/testsuite/cargo_add/empty_dep_table/in

@@ -0,0 +1 @@
+../add-basic.in

tests/testsuite/cargo_add/empty_dep_table/mod.rs

@@ -0,0 +1,25 @@
+use cargo_test_support::compare::assert_ui;
+use cargo_test_support::prelude::*;
+use cargo_test_support::Project;
+
+use crate::cargo_add::init_registry;
+use cargo_test_support::curr_dir;
+
+#[cargo_test]
+fn case() {
+    init_registry();
+    let project = Project::from_template(curr_dir!().join("in"));
+    let project_root = project.root();
+    let cwd = &project_root;
+
+    snapbox::cmd::Command::cargo_ui()
+        .arg("add")
+        .arg_line("your-face --features eyes")
+        .current_dir(cwd)
+        .assert()
+        .code(101)
+        .stdout_matches_path(curr_dir!().join("stdout.log"))
+        .stderr_matches_path(curr_dir!().join("stderr.log"));
+
+    assert_ui().subset_matches(curr_dir!().join("out"), &project_root);
+}

tests/testsuite/cargo_add/empty_dep_table/out/Cargo.toml

@@ -0,0 +1,8 @@
+[workspace]
+
+[package]
+name = "cargo-list-test-fixture"
+version = "0.0.0"
+
+[dependencies]
+your-face = { }

tests/testsuite/cargo_add/empty_dep_table/stderr.log

@@ -0,0 +1 @@
+error: Unrecognized dependency source for `your-face`, expected a table with a `version`, `git`, `path`, or `workspace` key

tests/testsuite/cargo_add/mod.rs

@@ -15,6 +15,7 @@ mod dev;
 mod dev_build_conflict;
 mod dev_prefer_existing_version;
 mod dry_run;
+mod empty_dep_table;
 mod features;
 mod features_empty;
 mod features_multiple_occurrences;