Function _buildDependencyGraph

src/spec-configuration/containerFeaturesOrder.ts:345–477

(
	params: CommonParams,
	processFeature: (userFeature: DevContainerFeature) => Promise<FeatureSet | undefined>,
	worklist: FNode[],
	acc: FNode[],
	lockfile: Lockfile | undefined)

}

async function _buildDependencyGraph(
	params: CommonParams,
	processFeature: (userFeature: DevContainerFeature) => Promise<FeatureSet | undefined>,
	worklist: FNode[],
	acc: FNode[],
	lockfile: Lockfile | undefined): Promise<DependencyGraph> {
	const { output } = params;

	while (worklist.length > 0) {
		const current = worklist.shift()!;

		output.write(`Resolving Feature dependencies for '${current.userFeatureId}'...`, LogLevel.Info);

		const processedFeature = await processFeature(current);
		if (!processedFeature) {
			throw new Error(`ERR: Feature '${current.userFeatureId}' could not be processed.  You may not have permission to access this Feature, or may not be logged in.  If the issue persists, report this to the Feature author.`);
		}

		// Set the processed FeatureSet object onto Node.
		current.featureSet = processedFeature;

		// If the current Feature is already in the accumulator, skip it.
		// This stops cycles but doesn't report them.  
		// Cycles/inconsistencies are thrown as errors in the next stage (rounds).
		if (acc.some(f => equals(params, f, current))) {
			continue;
		}

		const type = processedFeature.sourceInformation.type;
		let metadata: Feature | undefined;
		// Switch on the source type of the provided Feature.
		// Retrieving the metadata for the Feature (the contents of 'devcontainer-feature.json')
		switch (type) {
			case 'oci':
				metadata = await getOCIFeatureMetadata(params, current);
				break;

			case 'file-path':
				const filePath = (current.featureSet.sourceInformation as FilePathSourceInformation).resolvedFilePath;
				const metadataFilePath = path.join(filePath, DEVCONTAINER_FEATURE_FILE_NAME);
				if (!isLocalFile(filePath)) {
					throw new Error(`Metadata file '${metadataFilePath}' cannot be read for Feature '${current.userFeatureId}'.`);
				}
				const serialized = (await readLocalFile(metadataFilePath)).toString();
				if (serialized) {
					metadata = jsonc.parse(serialized) as Feature;
				}
				break;

			case 'direct-tarball':
				const tarballUri = (processedFeature.sourceInformation as DirectTarballSourceInformation).tarballUri;
				const expectedDigest = lockfile?.features[tarballUri]?.integrity;
				metadata = await getTgzFeatureMetadata(params, current, expectedDigest);
				break;

			default:
				// Legacy
				// No dependency metadata to retrieve.