How to create an array in Helm templates with contents of YAML files as items

I have a few YAML files in my chart directory and, in my template, I want use their contents in an array. For example, if I had 2 files:

# file-a.yaml:
name: abc

# file-b.yaml:
name: xyz

And my template:

      {{ printf "files:" | nindent 8 -}}
        {{- range $stagesPath, $fileContent := $.Files.Glob (printf "files/*.yaml") }}
          - {{ $.Files.Get $stagesPath | toYaml | nindent 10 }}
        {{- end }}

would render:

        files:
          -
          |
            name: abc
          -
          |
            name: xyz

But I want:

        files:
          - name: abc
          - name: xyz

Can you please help me? :)

.Files.Get already returns a string. When you pipe it through toYaml, the string winds up double-escaped. That might be why you're winding up with YAML block-scalar syntax.

Since you already have the file content as a string, you don't need toYaml. You do need to indent it to fit correctly in the containing YAML block syntax, but then trim the leading whitespace so the first line isn't over-indented.

        files:
{{- range $stagesPath := $.Files.Glob (printf "files/*.yaml") }}
          - {{ $.Files.Get $stagesPath | indent 10 | trim }}
{{- end }}

In principle you could use fromYaml to parse the file content into a structured value. The templating language doesn't have any sort of map function, so building a list of data values and then dumping it out is tricky. This probably works (reading each file, parsing it fromYaml, collecting each item into a list, and then putting the whole list through toYaml once):

{{- $files := list }}
{{- range $stagesPath := .Files.Glob "files/*.yaml" }}
{{- $files = append $files ($.Files.Get $stagesPath | fromYaml) }}
{{- end }}
        files: {{- $files | toYaml | nindent 10 }}