Kotlin script to generate GitHub Actions README documentation from Action inputs

convert.main.kts

#!/usr/bin/env kotlin

@file:DependsOn("com.fasterxml.jackson.module:jackson-module-kotlin:2.14.2")
@file:DependsOn("com.fasterxml.jackson.datatype:jackson-datatype-jdk8:2.14.2")
@file:DependsOn("com.fasterxml.jackson.dataformat:jackson-dataformat-yaml:2.14.2")
@file:DependsOn("com.fasterxml.jackson.core:jackson-databind:2.14.2")

import com.fasterxml.jackson.databind.ObjectMapper
import com.fasterxml.jackson.dataformat.yaml.YAMLFactory
import com.fasterxml.jackson.module.kotlin.KotlinModule
import com.fasterxml.jackson.module.kotlin.readValue

val inputYaml = """
  some-foo:
    description: The foo that you foo with.
    required: true
  some-bar:
    description: The bar for the foo
  some-baz:
    description: The baz
    default: reasonable-baz
""".trimIndent()

data class InputField(
    val description: String? = "",
    val required: Boolean = false,
    val default: String? = "",
    val type: String? = "",
)

val yamlMapper = ObjectMapper(YAMLFactory()).apply { registerModule(KotlinModule()) }
val inputs = yamlMapper.readValue<Map<String, InputField>>(inputYaml)

val maxNameLength = inputs.keys.maxOf { it.length }
val nameHeader = "Name".padEnd(length = maxNameLength, padChar = ' ')

val maxRequiredLength = 8
val requiredHeader = "Required".padEnd(length = maxRequiredLength, padChar = ' ')

val maxDefaultLength = inputs.values.maxOf { it.default?.length ?: 8 }
val defaultHeader = "Default".padEnd(length = maxDefaultLength, padChar = ' ')

val maxDescriptionLength = inputs.values.maxOf { it.description?.length ?: 12 }
val descriptionHeader = "Description".padEnd(length = maxDescriptionLength, padChar = ' ')

val spacer = "-"

fun spacerFor(length: Int): String = spacer.padEnd(length = length, padChar = '-')

val rows = inputs.map {
"""
| ${it.key.padEnd(length = maxNameLength, padChar = ' ')}
 | ${(if (it.value.required) "X" else "").padEnd(length = maxRequiredLength, padChar = ' ')}
 | ${it.value.default?.padEnd(length = maxDefaultLength, padChar = ' ')}
 | ${it.value.description?.padEnd(length = maxDescriptionLength, padChar = ' ')}
 |
""".replace("\n", "")
}.joinToString(separator = "\n")

val output = """
| $nameHeader | $requiredHeader | $defaultHeader | $descriptionHeader |
|-${spacerFor(maxNameLength)}-|-${spacerFor(maxRequiredLength)}-|-${spacerFor(maxDefaultLength)}-|-${spacerFor(maxDescriptionLength)}-|
$rows
""".trimIndent()

println(output)

Name	Required	Default	Description
some-foo	X		The foo that you foo with.
some-bar			The bar for the foo
some-baz		reasonable-baz	The baz