write-tests

name	write-tests
description	Write tests for Syncpack using the TestBuilder pattern. Use when adding tests for commands, validation logic, or any new functionality. Covers TestBuilder API, assertion patterns, and common test scenarios.

Write Tests

Golden rules

• Use TestBuilder — never construct Context manually.
• Assert with expect(&ctx).to_have_instances(vec![...]) — never index ctx.instances.
• Async-first: #[tokio::test] + .run().await is the canonical entry.

TDD

1. Read 2-3 tests in the same *_test.rs and copy the pattern
2. Write failing test → just test → confirm RED
3. Ask before implementing
4. Implement minimal code → GREEN → just format

Quick start

use {
  crate::{
    instance::{FixableInstance::*, InstanceState, SuspectInstance::*, UnfixableInstance::*, ValidInstance::*},
    test::{
      builder::TestBuilder,
      expect::{expect, ExpectedInstance},
    },
  },
  serde_json::json,
};

#[tokio::test]
async fn pinned_version_replaces_anything_different() {
  let ctx = TestBuilder::new()
    .with_package(json!({
      "name": "package-a",
      "version": "1.0.0",
      : {: }
    }))
    .(json!({
      : [],
      : 
    }))
    .()
    .;
  (&ctx).([
    ExpectedInstance {
      state: InstanceState::(IsLocalAndValid),
      dependency_name: ,
      id: ,
      actual: ,
      expected: (),
      overridden: ,
    },
    ExpectedInstance {
      state: InstanceState::(DiffersToPin),
      dependency_name: ,
      id: ,
      actual: ,
      expected: (),
      overridden: ,
    },
  ]);
}