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docs: Clarify Files.Lines behavior for empty and missing files #2174

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docs: clarify Files.Lines behavior for empty and missing files
promptless[bot] Jul 8, 2026
d24b123
Merge remote-tracking branch 'origin/main' into promptless/files-line…
promptless[bot] Jul 20, 2026
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5 changes: 3 additions & 2 deletions docs/chart_template_guide/accessing_files.md
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Original file line number Diff line number Diff line change
Expand Up @@ -235,8 +235,9 @@ data:
{{ . }}{{ end }}
```

If the file is empty or does not exist, `Lines` returns an empty list. In that
case, a `range` over it simply produces no output instead of failing.
If the file you reference is empty or does not exist, `Lines` returns an empty

@promptless-for-oss promptless-for-oss Jul 8, 2026

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Applied the same Lines note to the current (v4) docs because PR #32303 is the v3 backport of #32290, which lands the identical pkg/engine/files.go fix on main, so the empty-file behavior holds for v4 as well.

Source: helm/helm#32290

list rather than failing. The `range` loop then produces no output, so
referencing a missing or empty file will not cause template rendering to fail.

There is no way to pass files external to the chart during `helm install`. So if
you are asking users to supply data, it must be loaded using `helm install -f`
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4 changes: 4 additions & 0 deletions versioned_docs/version-3/chart_template_guide/accessing_files.md
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Expand Up @@ -235,6 +235,10 @@ data:
{{ . }}{{ end }}
```

If the file you reference is empty or does not exist, `Lines` returns an empty

@promptless-for-oss promptless-for-oss Jul 8, 2026

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Added the empty/missing-file note because this PR changes files.Lines in pkg/engine/files.go — the guard becomes len(f[path]) == 0 so empty files return an empty []string{} like missing files already did, instead of panicking with index-out-of-range and failing the render.

Source: helm/helm#32303

list rather than failing. The `range` loop then produces no output, so
referencing a missing or empty file will not cause template rendering to fail.

There is no way to pass files external to the chart during `helm install`. So if
you are asking users to supply data, it must be loaded using `helm install -f`
or `helm install --set`.
Expand Down
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