test(docker_context): Add basic tests to module (#2205)

* test(docker_context): Add basic tests to module

This adds some basic tests to the docker_context module.

* PR suggestion

2 files changed, 187 insertions, 2 deletions

diff --git a/docs/config/README.md b/docs/config/README.md
index c9c0adb1a..533de1e31 100644
--- a/docs/config/README.md
+++ b/docs/config/README.md
@@ -716,8 +716,8 @@ The `docker_context` module shows the currently active
 | `format`          | `"via [$symbol$context]($style) "` | The format for the module.                                                                                      |
 | `symbol`          | `"🐳 "`                            | The symbol used before displaying the Docker context.                                                           |
 | `style`           | `"blue bold"`                      | The style for the module.                                                                                       |
-| `only_with_files` | `false`                            | Only show when there's a `docker-compose.yml`, `docker-compose.yaml`, or `Dockerfile` in the current directory. |
-| `disabled`        | `true`                             | Disables the `docker_context` module.                                                                           |
+| `only_with_files` | `true`                             | Only show when there's a `docker-compose.yml`, `docker-compose.yaml`, or `Dockerfile` in the current directory. |
+| `disabled`        | `false`                            | Disables the `docker_context` module.                                                                           |
 
 ### Variables
 
diff --git a/src/modules/docker_context.rs b/src/modules/docker_context.rs
index c30a6bdf5..23840888b 100644
--- a/src/modules/docker_context.rs
+++ b/src/modules/docker_context.rs
@@ -77,3 +77,188 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         _ => None,
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::test::ModuleRenderer;
+    use ansi_term::Color;
+    use std::fs::File;
+    use std::io::{self, Write};
+
+    #[test]
+    fn only_trigger_when_docker_config_exists() -> io::Result<()> {
+        let cfg_dir = tempfile::tempdir()?;
+        let actual = ModuleRenderer::new("docker_context")
+            .env("DOCKER_CONFIG", cfg_dir.path().to_string_lossy())
+            .collect();
+        let expected = None;
+
+        assert_eq!(expected, actual);
+        cfg_dir.close()
+    }
+
+    #[test]
+    fn test_with_docker_compose_yml() -> io::Result<()> {
+        let cfg_dir = tempfile::tempdir()?;
+        let cfg_file = cfg_dir.path().join("config.json");
+
+        let pwd = tempfile::tempdir()?;
+        File::create(pwd.path().join("docker-compose.yml"))?.sync_all()?;
+
+        let config_content = serde_json::json!({
+            "currentContext": "starship"
+        });
+
+        let mut docker_config = File::create(&cfg_file)?;
+        docker_config.write_all(config_content.to_string().as_bytes())?;
+        docker_config.sync_all()?;
+
+        let actual = ModuleRenderer::new("docker_context")
+            .env("DOCKER_CONFIG", cfg_dir.path().to_string_lossy())
+            .path(pwd.path())
+            .collect();
+
+        let expected = Some(format!("via {} ", Color::Blue.bold().paint("🐳 starship")));
+
+        assert_eq!(expected, actual);
+
+        cfg_dir.close()?;
+        pwd.close()
+    }
+
+    #[test]
+    fn test_with_docker_compose_yaml() -> io::Result<()> {
+        let cfg_dir = tempfile::tempdir()?;
+        let cfg_file = cfg_dir.path().join("config.json");
+
+        let pwd = tempfile::tempdir()?;
+        File::create(pwd.path().join("docker-compose.yaml"))?.sync_all()?;
+
+        let config_content = serde_json::json!({
+            "currentContext": "starship"
+        });
+
+        let mut docker_config = File::create(&cfg_file)?;
+        docker_config.write_all(config_content.to_string().as_bytes())?;
+        docker_config.sync_all()?;
+
+        let actual = ModuleRenderer::new("docker_context")
+            .env("DOCKER_CONFIG", cfg_dir.path().to_string_lossy())
+            .path(pwd.path())
+            .collect();
+
+        let expected = Some(format!("via {} ", Color::Blue.bold().paint("🐳 starship")));
+
+        assert_eq!(expected, actual);
+
+        cfg_dir.close()?;
+        pwd.close()
+    }
+
+    #[test]
+    fn test_with_dockerfile() -> io::Result<()> {
+        let cfg_dir = tempfile::tempdir()?;
+        let cfg_file = cfg_dir.path().join("config.json");
+
+        let pwd = tempfile::tempdir()?;
+        File::create(pwd.path().join("Dockerfile"))?.sync_all()?;
+
+        let config_content = serde_json::json!({
+            "currentContext": "starship"
+        });
+
+        let mut docker_config = File::create(&cfg_file)?;
+        docker_config.write_all(config_content.to_string().as_bytes())?;
+        docker_config.sync_all()?;
+
+        let actual = ModuleRenderer::new("docker_context")
+            .env("DOCKER_CONFIG", cfg_dir.path().to_string_lossy())
+            .path(pwd.path())
+            .collect();
+
+        let expected = Some(format!("via {} ", Color::Blue.bold().paint("🐳 starship")));
+
+        assert_eq!(expected, actual);
+
+        cfg_dir.close()?;
+        pwd.close()
+    }
+
+    #[test]
+    fn test_no_docker_files() -> io::Result<()> {
+        let cfg_dir = tempfile::tempdir()?;
+        let cfg_file = cfg_dir.path().join("config.json");
+
+        let config_content = serde_json::json!({
+            "currentContext": "starship"
+        });
+
+        let mut docker_config = File::create(&cfg_file)?;
+        docker_config.write_all(config_content.to_string().as_bytes())?;
+        docker_config.sync_all()?;
+
+        let actual = ModuleRenderer::new("docker_context")
+            .env("DOCKER_CONFIG", cfg_dir.path().to_string_lossy())
+            .collect();
+
+        let expected = None;
+
+        assert_eq!(expected, actual);
+
+        cfg_dir.close()
+    }
+
+    #[test]
+    fn test_no_scan_for_docker_files() -> io::Result<()> {
+        let cfg_dir = tempfile::tempdir()?;
+        let cfg_file = cfg_dir.path().join("config.json");
+
+        let config_content = serde_json::json!({
+            "currentContext": "starship"
+        });
+
+        let mut docker_config = File::create(&cfg_file)?;
+        docker_config.write_all(config_content.to_string().as_bytes())?;
+        docker_config.sync_all()?;
+
+        let actual = ModuleRenderer::new("docker_context")
+            .env("DOCKER_CONFIG", cfg_dir.path().to_string_lossy())
+            .config(toml::toml! {
+                [docker_context]
+                only_with_files = false
+            })
+            .collect();
+
+        let expected = Some(format!("via {} ", Color::Blue.bold().paint("🐳 starship")));
+
+        assert_eq!(expected, actual);
+
+        cfg_dir.close()
+    }
+
+    #[test]
+    fn test_invalid_json() -> io::Result<()> {
+        let cfg_dir = tempfile::tempdir()?;
+        let cfg_file = cfg_dir.path().join("config.json");
+
+        let config_content = "not valid json";
+
+        let mut docker_config = File::create(&cfg_file)?;
+        docker_config.write_all(config_content.to_string().as_bytes())?;
+        docker_config.sync_all()?;
+
+        let actual = ModuleRenderer::new("docker_context")
+            .env("DOCKER_CONFIG", cfg_dir.path().to_string_lossy())
+            .config(toml::toml! {
+                [docker_context]
+                only_with_files = false
+            })
+            .collect();
+
+        let expected = None;
+
+        assert_eq!(expected, actual);
+
+        cfg_dir.close()
+    }
+}