fix: blank lines in description produce whitespace-only lines in YAML frontmatter

[javabrett]

Summary

When a provider resource's Description (or MarkdownDescription) contains blank lines — for example, surrounding a code fence — the generated YAML frontmatter ends up with whitespace-only lines ( , two spaces) instead of genuinely blank lines.

Root cause

PrefixLines in internal/tmplfuncs/tmplfuncs.go was implemented as:

return prefix + strings.Join(strings.Split(text, "\n"), "\n"+prefix)

strings.Split produces an empty string "" for each blank line. strings.Join then inserts "\n" + prefix before that empty string, yielding a line that is just the prefix (e.g. " ") with no content.

The prefixlines " " template filter is used in the YAML frontmatter block scalar in all four default templates (resource, data source, function, action):

description: |-
{{ .Description | plainmarkdown | trimspace | prefixlines "  " }}

So any blank line in a provider description becomes a whitespace-only line in the generated docs/ output.

Fix

Skip adding the prefix when the line is empty:

lines := strings.Split(text, "\n")
for i, line := range lines {
    if line != "" {
        lines[i] = prefix + line
    }
}
return strings.Join(lines, "\n")

Tests

Added internal/tmplfuncs/tmplfuncs_test.go with unit tests for PrefixLines, including the blank-line regression case. The failing test case with the old implementation:

• Input: "line1\n\nline3", prefix " "
• Old output: " line1\n \n line3" (middle line is " ", two spaces)
• New output: " line1\n\n line3" (middle line is empty)

The existing TestRenderStringTemplate in internal/provider/template_test.go continues to pass unchanged.

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