CUE: File content injection

deliverable.cue

#Embed: {
	files: [string]: string
}

#Resource: {
	#embed: [string]: #Embed | *{}
	...
}

#Deliverable: {
	destination: string
	resources: [...#Resource]
}

dump_tool.cue

command: dump: X={
	for name, deliverable in deliverables {
		for resource in deliverable.resources {
			// Inject external file content
			for embedVarName, embed in resource.#embed {
				for i, f in embed.files {
					"\(f)": file.Read & {
						filename: f
						contents: string
					}
					// hack: read the file content before write resource
					"print-\(f)": os.Getenv & {
						"dummy": X[f].contents
					}
				}
			}
		}

		"write-\(name)": file.Create & {
			filename: deliverable.destination
			contents: yaml.MarshalStream([ for x in deliverable.resources {
				x & {
					for embedVarName, embed in x.#embed {
						"\(embedVarName)": [ for f in embed.files {
							{
								"\(f)": X[f].contents
							}
						}]
					}
				}
			}])
		}
	}
}

sample-deliverable.cue

deliverables: sample: #Deliverable & {
	destination: "foo.yaml"
	resources: [ #Resource & {
		// Special field for embedding
		#embed: {
			// target variable name
			"a": {
				files: {
					// filename to filepath
					"config.yaml": "path/to/config.yaml"
				}
			}
		}

		// Injection target
		a: _ | *""
	}]
}