Structure

Demo pipeline

The project already contains three components which are used to create a Nextflow pipeline with the following topology:

graph LR
   A(file?.tsv) --> B[/remove_comments/]
   B --> C[/take_column/]
   C --> D[/combine_columns/]
   D --> E(output)

Diagram of the pipeline topology

remove_comments is a Bash script which removes all lines starting with a # from a file.
take_column is a Python script which extracts one of the columns in a TSV file.
combine_columns is an R script which combines multiple files into a TSV.

A namespace is effectively a hierarchical grouping of the components in the src/ directory. Here are some benefits of grouping your components:

Grouping components in namespaces allows for categorizing components.
Each teams of developers can work on a different set of components in parallel, which improves the separation of concerns.
Generating build targets and unit testing can be done in bulk, with optional filtering by namespace using the viash ns commands.

This guide will cover how to define a namespace and use it with Viash.

You can assign a component to a namespace by defining its namespace attribute in the Viash config file:

name: some_component
namespace: some_namespace/subnamespace
...

Typically, the Viash config for this component will be located at src/some_namespace/subnamespace/some_component/config.vsh.yaml.