Merge pull request #35 from anthonyoteri/unit-tests

Cargo.toml

@@ -18,3 +18,6 @@ thiserror = "1.0.48"
 toml = "0.8.0"
 url = { version = "2.4.1", features = ["serde"] }
 xdg = "2.5.2"
+
+[dev-dependencies]
+mockito = "1.2.0"

src/commands.rs

@@ -14,6 +14,8 @@
  *    limitations under the License.
  */
 
+use std::io::Write;
+
 use serde::Deserialize;
 use url::Url;
 
@@ -29,7 +31,7 @@ use crate::error::ApiError;
 ///
 /// Returns an `ApiError` if there is a problem fetching or parsing the
 /// responses from the Docker Registry API.  
-pub async fn catalog_handler(registry_url: &Url) -> Result<(), ApiError> {
+pub async fn catalog_handler(buf: &mut dyn Write, registry_url: &Url) -> Result<(), ApiError> {
     #[derive(Deserialize)]
     struct Response {
         repositories: Vec<String>,
@@ -45,7 +47,7 @@ pub async fn catalog_handler(registry_url: &Url) -> Result<(), ApiError> {
         .collect();
 
     for repository in repository_list {
-        println!("{repository}");
+        writeln!(buf, "{repository}")?;
     }
 
     Ok(())
@@ -60,7 +62,11 @@ pub async fn catalog_handler(registry_url: &Url) -> Result<(), ApiError> {
 ///
 /// Returns an `ApiError` if there is a problem fetching or parsing the
 /// responses from the Docker Registry API.  
-pub async fn tags_handler(registry_url: &Url, name: &str) -> Result<(), ApiError> {
+pub async fn tags_handler(
+    buf: &mut dyn Write,
+    registry_url: &Url,
+    name: &str,
+) -> Result<(), ApiError> {
     #[derive(Deserialize)]
     struct Response {
         tags: Vec<String>,
@@ -76,7 +82,7 @@ pub async fn tags_handler(registry_url: &Url, name: &str) -> Result<(), ApiError
         .collect();
 
     for tag in tag_list {
-        println!("{tag}");
+        writeln!(buf, "{tag}")?;
     }
 
     Ok(())
@@ -89,7 +95,12 @@ pub async fn tags_handler(registry_url: &Url, name: &str) -> Result<(), ApiError
 /// Returns an `ApiError` if there is a problem fetching the manifest or if there
 /// is a problem parsing the response from the Docker Registry API.
 #[allow(clippy::unused_async)]
-pub async fn show_handler(registry_url: &Url, image: &str, tag: &str) -> Result<(), ApiError> {
+pub async fn show_handler(
+    _buf: &mut dyn Write,
+    registry_url: &Url,
+    image: &str,
+    tag: &str,
+) -> Result<(), ApiError> {
     log::trace!("show_handler(registry_url: {registry_url:?}, image: {image}, tag: {tag})");
     let path = format!("/v2/{image}/manifests/{tag}");
     let _url = registry_url.join(&path)?;
@@ -104,7 +115,12 @@ pub async fn show_handler(registry_url: &Url, image: &str, tag: &str) -> Result<
 /// manifest digest, or if there is a problem deleting the manifest from the
 /// Docker Registry API.
 #[allow(clippy::unused_async)]
-pub async fn delete_handler(registry_url: &Url, image: &str, tag: &str) -> Result<(), ApiError> {
+pub async fn delete_handler(
+    _buf: &mut dyn Write,
+    registry_url: &Url,
+    image: &str,
+    tag: &str,
+) -> Result<(), ApiError> {
     log::trace!("delete_handler(registry_url: {registry_url:?}, image: {image}, tag: {tag})");
     todo!()
 }
@@ -117,7 +133,7 @@ pub async fn delete_handler(registry_url: &Url, image: &str, tag: &str) -> Resul
 ///
 /// Returns an `ApiError` if there is a problem communicating with the
 /// endpoint or if the required version is not supported.
-pub async fn check_handler(registry_url: &Url) -> Result<(), ApiError> {
+pub async fn check_handler(buf: &mut dyn Write, registry_url: &Url) -> Result<(), ApiError> {
     log::trace!("check_handler(registry_url: {registry_url:?})");
 
     let path = "/v2";
@@ -125,5 +141,246 @@ pub async fn check_handler(registry_url: &Url) -> Result<(), ApiError> {
 
     let response = reqwest::get(url).await?;
     api::parse_response_status(&response)?;
+    writeln!(buf, "Ok")?;
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use std::error::Error;
+
+    use url::Url;
+
+    use crate::error;
+
+    use super::*;
+
+    /// Validate the happy path for the catalog handler.
+    ///
+    /// This test spins up a mock server, and makes a request to the catalog
+    /// endpoint.  It checks that the handler both called the request the
+    /// expected number of times, and did not return an error.
+    #[async_std::test]
+    async fn test_catalog_handler() {
+        let mut server = mockito::Server::new_async().await;
+        let path = "/v2/_catalog";
+
+        let registry_url = Url::parse(&server.url()).expect("Failed to parse registry URL");
+        let mock_response = server
+            .mock("GET", path)
+            .with_status(http::status::StatusCode::OK.as_u16().into())
+            .with_header(http::header::CONTENT_TYPE.as_str(), "application/json")
+            .with_body(r#"{"repositories": ["image1", "image2", "image3"]}"#)
+            .create();
+
+        let mut buf: Vec<u8> = Vec::new();
+        let result = catalog_handler(&mut buf, &registry_url).await;
+        assert!(result.is_ok());
+        assert_eq!(String::from_utf8(buf).unwrap(), *"image1\nimage2\nimage3\n");
+
+        mock_response.assert();
+    }
+
+    /// Validate the pagination of the catalog handler.
+    ///
+    /// This test spins up a mock server, and makes a request to the catalog
+    /// endpoint.  The response includes a pagination link, which the handler
+    /// should follow, resulting in the combined list.  It checks that the
+    /// handler both called the request the expected number of times, and did
+    /// not return an error.
+    #[async_std::test]
+    async fn test_catalog_handler_with_pagination() {
+        let mut server = mockito::Server::new_async().await;
+        let path = "/v2/_catalog";
+        let path2 = "/v2/_catalog?n=2,last=image2";
+
+        let registry_url = Url::parse(&server.url()).expect("Failed to parse registry URL");
+        let mock_response = server
+            .mock("GET", path)
+            .with_status(http::status::StatusCode::OK.as_u16().into())
+            .with_header(http::header::CONTENT_TYPE.as_str(), "application/json")
+            .with_header(
+                http::header::LINK.as_str(),
+                &format!(r#"<{path2}>; rel=next"#),
+            )
+            .with_body(r#"{"repositories": ["image1", "image2"]}"#)
+            .create();
+
+        let mock_response2 = server
+            .mock("GET", path2)
+            .with_status(http::status::StatusCode::OK.as_u16().into())
+            .with_header(http::header::CONTENT_TYPE.as_str(), "application/json")
+            .with_body(r#"{"repositories": ["image3"]}"#)
+            .create();
+
+        let mut buf: Vec<u8> = Vec::new();
+        let result = catalog_handler(&mut buf, &registry_url).await;
+        assert!(result.is_ok());
+        assert_eq!(String::from_utf8(buf).unwrap(), *"image1\nimage2\nimage3\n");
+
+        mock_response.assert();
+        mock_response2.assert();
+    }
+
+    /// Validate the happy path for the tags handler.
+    ///
+    /// This test spins up a mock server, and makes a request to the tags
+    /// endpoint.  It checks that the handler both called the request the
+    /// expected number of times, and did not return an error.
+    #[async_std::test]
+    async fn test_tags_handler() {
+        let mut server = mockito::Server::new_async().await;
+        let path = "/v2/some_image/tags/list";
+
+        // Mock the HTTP response for the Docker Registry API
+        let registry_url = Url::parse(&server.url()).expect("Failed to parse registry URL");
+        let mock_response = server
+            .mock("GET", path)
+            .with_status(http::status::StatusCode::OK.as_u16().into())
+            .with_header(http::header::CONTENT_TYPE.as_str(), "application/json")
+            .with_body(r#"{"tags": ["tag1", "tag2", "tag3"]}"#)
+            .create();
+
+        let mut buf: Vec<u8> = Vec::new();
+        let result = tags_handler(&mut buf, &registry_url, "some_image").await;
+        assert!(result.is_ok());
+        assert_eq!(String::from_utf8(buf).unwrap(), *"tag1\ntag2\ntag3\n");
+
+        mock_response.assert();
+    }
+
+    /// Validate the pagination of the catalog handler.
+    ///
+    /// This test spins up a mock server, and makes a request to the catalog
+    /// endpoint.  The response includes a pagination link, which the handler
+    /// should follow, resulting in the combined list.  It checks that the
+    /// handler both called the request the expected number of times, and did
+    /// not return an error.
+    #[async_std::test]
+    async fn test_tags_handler_with_pagination() {
+        let mut server = mockito::Server::new_async().await;
+        let path = "/v2/some_image/tags/list";
+        let path2 = "/v2/some_image/tags/list?n=2,last=tag2";
+
+        // Mock the HTTP response for the Docker Registry API
+        let registry_url = Url::parse(&server.url()).expect("Failed to parse registry URL");
+        let mock_response = server
+            .mock("GET", path)
+            .with_status(http::status::StatusCode::OK.as_u16().into())
+            .with_header(http::header::CONTENT_TYPE.as_str(), "application/json")
+            .with_header(
+                http::header::LINK.as_str(),
+                &format!(r#"<{path2}>; rel=next"#),
+            )
+            .with_body(r#"{"tags": ["tag1", "tag2"]}"#)
+            .create();
+
+        let mock_response2 = server
+            .mock("GET", path2)
+            .with_status(http::status::StatusCode::OK.as_u16().into())
+            .with_header(http::header::CONTENT_TYPE.as_str(), "application/json")
+            .with_body(r#"{"tags": ["tag3"]}"#)
+            .create();
+
+        let mut buf: Vec<u8> = Vec::new();
+        let result = tags_handler(&mut buf, &registry_url, "some_image").await;
+        assert!(result.is_ok());
+        assert_eq!(String::from_utf8(buf).unwrap(), *"tag1\ntag2\ntag3\n");
+
+        mock_response.assert();
+        mock_response2.assert();
+    }
+
+    /// Validate the happy path for the check handler.
+    ///
+    /// This test spins up a mock server, and makes a request to the check
+    /// endpoint.  It checks that the handler both called the request the
+    /// expected number of times, and did not return an error.
+    #[async_std::test]
+    async fn test_check_handler() {
+        let mut server = mockito::Server::new_async().await;
+        let path = "/v2";
+
+        // Mock the HTTP response for the Docker Registry API
+        let registry_url = Url::parse(&server.url()).expect("Failed to parse registry URL");
+        let mock_response = server
+            .mock("GET", path)
+            .with_status(http::status::StatusCode::OK.as_u16().into())
+            .with_header(http::header::CONTENT_TYPE.as_str(), "application/json")
+            .with_header("Docker-Distribution-API-Version", "registry/2.0")
+            .create();
+
+        let mut buf: Vec<u8> = Vec::new();
+        let result = check_handler(&mut buf, &registry_url).await;
+        assert!(result.is_ok());
+        assert_eq!(String::from_utf8(buf).unwrap(), *"Ok\n");
+
+        mock_response.assert();
+    }
+
+    /// Validate the the check handler on invalid API version
+    ///
+    /// This validates that if the "Docker-Distribution-API-Version" header
+    /// is missing in the response, the appropriate error is returned.
+    #[async_std::test]
+    async fn test_check_handler_missing_api_version() -> Result<(), Box<dyn Error>> {
+        let mut server = mockito::Server::new_async().await;
+        let path = "/v2";
+
+        // Mock the HTTP response for the Docker Registry API
+        let registry_url = Url::parse(&server.url()).expect("Failed to parse registry URL");
+        let mock_response = server
+            .mock("GET", path)
+            .with_status(http::status::StatusCode::OK.as_u16().into())
+            .with_header(http::header::CONTENT_TYPE.as_str(), "application/json")
+            .create();
+
+        let mut buf: Vec<u8> = Vec::new();
+        let result = check_handler(&mut buf, &registry_url).await;
+
+        // Ensure that we got the correct error type.
+        assert!(result.is_err());
+        let err = result.unwrap_err();
+        match err {
+            error::ApiError::UnexpectedResponse(_) => Ok(()),
+            e => Err(e),
+        }?;
+
+        mock_response.assert();
+        Ok(())
+    }
+
+    /// Validate the the check handler on invalid API version
+    ///
+    /// This validates that if the "Docker-Distribution-API-Version" header
+    /// is present in the response but contains an unexpected value, the
+    /// appropriate error is returned.
+    #[async_std::test]
+    async fn test_check_handler_invalid_api_version() -> Result<(), Box<dyn Error>> {
+        let mut server = mockito::Server::new_async().await;
+        let path = "/v2";
+
+        // Mock the HTTP response for the Docker Registry API
+        let registry_url = Url::parse(&server.url()).expect("Failed to parse registry URL");
+        let mock_response = server
+            .mock("GET", path)
+            .with_status(http::status::StatusCode::OK.as_u16().into())
+            .with_header(http::header::CONTENT_TYPE.as_str(), "application/json")
+            .with_header("Docker-Distribution-API-Version", "registry/1.0")
+            .create();
+
+        let mut buf: Vec<u8> = Vec::new();
+        let result = check_handler(&mut buf, &registry_url).await;
+
+        // Ensure that we got the correct error type.
+        assert!(result.is_err());
+        let err = result.unwrap_err();
+        match err {
+            error::ApiError::UnsupportedVersion(_) => Ok(()),
+            e => Err(e),
+        }?;
+
+        mock_response.assert();
+        Ok(())
+    }
+}

src/error.rs

@@ -29,6 +29,9 @@ pub enum DredgeError {
     /// An error building the registry URL
     #[error("Error determining registry URL from {0}")]
     RegistryUrlError(String),
+
+    #[error(transparent)]
+    IOError(#[from] std::io::Error),
 }
 
 /// An error related to the communication with the registry API.
@@ -56,6 +59,9 @@ pub enum ApiError {
 
     #[error("Resource not found")]
     NotFound,
+
+    #[error(transparent)]
+    IOError(#[from] std::io::Error),
 }
 
 impl From<reqwest::header::ToStrError> for ApiError {

src/main.rs

@@ -17,6 +17,7 @@
 #![deny(clippy::pedantic)]
 
 use clap::Parser;
+use std::io::{self, Write};
 use url::Url;
 
 use crate::cli::Cli;
@@ -63,18 +64,26 @@ async fn main() -> Result<(), DredgeError> {
     let registry_url: Url = parse_registry_arg(&args.registry)?;
 
     // -- Dispatch control to the appropriate command handler.
+    let mut buf: Vec<u8> = Vec::new();
     match args.command {
-        Commands::Catalog => commands::catalog_handler(&registry_url).await?,
-        Commands::Tags { name } => commands::tags_handler(&registry_url, &name).await?,
+        Commands::Catalog => commands::catalog_handler(&mut buf, &registry_url).await?,
+        Commands::Tags { name } => commands::tags_handler(&mut buf, &registry_url, &name).await?,
         Commands::Show { image, tag } => {
-            commands::show_handler(&registry_url, &image, &tag.unwrap_or(LATEST.to_string()))
+            commands::show_handler(
+                &mut buf,
+                &registry_url,
+                &image,
+                &tag.unwrap_or(LATEST.to_string()),
+            )
             .await?;
         }
         Commands::Delete { image, tag } => {
-            commands::delete_handler(&registry_url, &image, &tag).await?;
+            commands::delete_handler(&mut buf, &registry_url, &image, &tag).await?;
         }
-        Commands::Check => commands::check_handler(&registry_url).await?,
+        Commands::Check => commands::check_handler(&mut buf, &registry_url).await?,
     }
 
+    io::stdout().write_all(&buf)?;
+
     Ok(())
 }