From 5b9d870b464053ec3cdf6bccca25b2a01cd21e74 Mon Sep 17 00:00:00 2001
From: qpismont <pismont.quentin@protonmail.com>
Date: Fri, 31 Jul 2026 20:18:29 +0000
Subject: [PATCH] Dockerfile field must be present

---
 crates/devcontainer-rs/src/lib.rs | 79 +++++++++++--------------------
 1 file changed, 27 insertions(+), 52 deletions(-)

diff --git a/crates/devcontainer-rs/src/lib.rs b/crates/devcontainer-rs/src/lib.rs
index 44c8bc3..1dd6d69 100644
--- a/crates/devcontainer-rs/src/lib.rs
+++ b/crates/devcontainer-rs/src/lib.rs
@@ -8,7 +8,7 @@ use serde::Deserialize;
 #[derive(Debug, Deserialize)]
 pub struct DevContainerBuildSchema {
     #[serde(default)]
-    pub dockerfile: Option<String>,
+    pub dockerfile: String,
     #[serde(default)]
     pub args: HashMap<String, String>,
 }
@@ -34,7 +34,6 @@ pub struct DevContainerSchema {
 
 #[derive(Debug)]
 pub struct DevContainer {
-    /// Absolute or relative path to the Dockerfile/Containerfile to build.
     pub container_file_path: PathBuf,
     pub name: Option<String>,
     pub build_args: HashMap<String, String>,
@@ -73,10 +72,7 @@ impl TryFrom<(DevContainerSchema, PathBuf)> for DevContainer {
             .parent()
             .ok_or_else(|| ParseError::InvalidDevContainerPath(devcontainer_path.clone()))?;
 
-        let container_file_path = match schema.build.dockerfile.as_deref() {
-            Some(file) => base_dir.join(file),
-            None => first_existing_container_file(base_dir),
-        };
+        let container_file_path = base_dir.join(schema.build.dockerfile);
 
         if !container_file_path.is_file() {
             return Err(ParseError::ContainerFileNotFound(container_file_path));
@@ -94,14 +90,6 @@ impl TryFrom<(DevContainerSchema, PathBuf)> for DevContainer {
     }
 }
 
-fn first_existing_container_file(base_dir: &Path) -> PathBuf {
-    ["Dockerfile", "Containerfile"]
-        .iter()
-        .map(|filename| base_dir.join(filename))
-        .find(|path| path.is_file())
-        .unwrap_or_else(|| base_dir.join("Dockerfile"))
-}
-
 pub async fn parse(path: impl AsRef<Path>) -> Result<DevContainer, ParseError> {
     let path = path.as_ref().to_path_buf();
     let contents = tokio::fs::read_to_string(&path)
@@ -126,50 +114,37 @@ mod tests {
     use super::*;
     use std::fs;
 
-    #[test]
-    fn resolves_configured_containerfile_relative_to_devcontainer_file() {
-        let dir = tempfile::tempdir().unwrap();
-        let devcontainer_path = dir.path().join("devcontainer.json");
-        let containerfile_path = dir.path().join("Containerfile");
-        fs::write(&containerfile_path, "FROM alpine\n").unwrap();
-
-        let schema = DevContainerSchema {
-            name: Some("test".into()),
-            build: DevContainerBuildSchema {
-                dockerfile: Some("Containerfile".into()),
-                args: HashMap::new(),
-            },
-            workspace_folder: None,
-            container_env: HashMap::new(),
-            post_create_command: None,
-            post_start_command: None,
-        };
-
-        let config = DevContainer::try_from((schema, devcontainer_path)).unwrap();
-        assert_eq!(config.container_file_path, containerfile_path);
-    }
-
-    #[test]
-    fn falls_back_to_dockerfile_before_containerfile() {
+    #[tokio::test]
+    async fn parses_devcontainer_file() {
         let dir = tempfile::tempdir().unwrap();
         let devcontainer_path = dir.path().join("devcontainer.json");
         let dockerfile_path = dir.path().join("Dockerfile");
+
         fs::write(&dockerfile_path, "FROM alpine\n").unwrap();
-        fs::write(dir.path().join("Containerfile"), "FROM busybox\n").unwrap();
+        fs::write(
+            &devcontainer_path,
+            r#"{
+                "name": "test",
+                "build": {
+                    "dockerfile": "Dockerfile",
+                    "args": {
+                        "VERSION": "1"
+                    }
+                },
+                "workspaceFolder": "/workspace",
+                "containerEnv": {
+                    "RUST_LOG": "debug"
+                }
+            }"#,
+        )
+        .unwrap();
 
-        let schema = DevContainerSchema {
-            name: None,
-            build: DevContainerBuildSchema {
-                dockerfile: None,
-                args: HashMap::new(),
-            },
-            workspace_folder: None,
-            container_env: HashMap::new(),
-            post_create_command: None,
-            post_start_command: None,
-        };
+        let config = parse(&devcontainer_path).await.unwrap();
 
-        let config = DevContainer::try_from((schema, devcontainer_path)).unwrap();
+        assert_eq!(config.name.as_deref(), Some("test"));
         assert_eq!(config.container_file_path, dockerfile_path);
+        assert_eq!(config.build_args.get("VERSION").unwrap(), "1");
+        assert_eq!(config.container_env.get("RUST_LOG").unwrap(), "debug");
+        assert_eq!(config.workspace_folder.as_deref(), Some("/workspace"));
     }
 }