Copy a directory into the output

Bring an existing file or directory tree into the output, templating text on the way.

Rendered from docs/how-to/copy-a-directory.md in the generator repository — where a correction belongs, and where the test suite runs every example on this page or states why it does not.

Copy brings in a file or a whole tree. Text files pass through the template system, so $$path$$ works in copied content; binaries are copied byte for byte.

The source tree is under tpl/. A templated asset, tpl/assets/logo.svg:

<svg><!-- $$title$$ --></svg>

Something a level deeper, tpl/assets/style/site.css:

body { font-family: sans-serif; }

And a single file to rename, tpl/readme.txt:

# $$title$$

import { Jostraca, Project, Folder, Copy } from 'jostraca'

const jostraca = Jostraca({ model: { title: 'My App' } })

await jostraca.generate({ folder: './out' }, () => {
  Project({ folder: 'app' }, () => {

    Folder({ name: 'static' }, () => {
      Copy({ from: './tpl/assets' })
    })

    Copy({ from: './tpl/readme.txt', to: 'README.txt' })
  })
})

app/README.txt
app/static/logo.svg
app/static/style/site.css

The tree keeps its shape, and $$title$$ was substituted in logo.svg:

<svg><!-- My App --></svg>

to renames a single file and names a subfolder for a directory. Both may contain slashes.

The one asymmetry to remember: a relative from resolves against the process working directory, not against the output folder the way Fragment’s from does. In a generator you publish, build an absolute path from import.meta.url rather than relying on where the user happened to be standing.

Text or binary is decided by the extension first, against a fixed list of around 250. Because no such list is complete, the content is then sniffed: a NUL byte in the first 8192 promotes an unlisted file to binary, which is what keeps .wasm and extensionless files intact.

Copy a directory into the output

See also#