Don't print help on empty args when envvars are present (#532)

CHANGELOG.md

@@ -40,6 +40,7 @@
 
 ### Fixed
 - Fixed excess arguments not being reported when `allowMultipleSubcommands=true` and a subcommand has excess arguments followed by another subcommand.
+- Commands with `printHelpOnEmptyArgs=true` will no longer print help if an option has a value from an environment variable or value source.  ([#382](https://github.com/ajalt/clikt/pull/382))
 
 ### Deprecated
 - Deprecated `Context.originalArgv`. It will now always return an empty list. If your commands need an argv, you can pass it to them before you run them, or set in on the new `Context.data` map.

clikt-mordant/src/commonTest/kotlin/com/github/ajalt/clikt/core/CliktCommandTest.kt

@@ -13,6 +13,7 @@ import com.github.ajalt.clikt.parameters.types.int
 import com.github.ajalt.clikt.testing.TestCommand
 import com.github.ajalt.clikt.testing.parse
 import com.github.ajalt.clikt.testing.test
+import com.github.ajalt.clikt.testing.withEnv
 import io.kotest.assertions.throwables.shouldThrow
 import io.kotest.data.blocking.forAll
 import io.kotest.data.row
@@ -81,12 +82,38 @@ class CliktCommandTest {
     @Test
     @JsName("printHelpOnEmptyArgs__true")
     fun `printHelpOnEmptyArgs = true`() {
-        class C : TestCommand(called = false, printHelpOnEmptyArgs = true)
+        class C : TestCommand(called = false, printHelpOnEmptyArgs = true) {
+            val r by option().required()
+        }
         shouldThrow<PrintHelpMessage> {
             C().parse("")
         }.error shouldBe true
     }
 
+    @Test
+    @JsName("printHelpOnEmptyArgs_with_envvars")
+    fun `printHelpOnEmptyArgs with envvars`() {
+        class C : TestCommand(called = true, printHelpOnEmptyArgs = true) {
+            val foo by option(envvar = "FOO")
+            override fun run_() {
+                foo shouldBe "bar"
+            }
+        }
+        C().withEnv("FOO" to "bar").parse("")
+    }
+
+    @Test
+    @JsName("printHelpOnEmptyArgs_with_envvars_and_required_option")
+    fun `printHelpOnEmptyArgs with envvars and required option`() {
+        class C : TestCommand(called = false, printHelpOnEmptyArgs = true) {
+            val foo by option(envvar = "FOO")
+            val r by option().required()
+        }
+        shouldThrow<MissingOption> {
+            C().withEnv("FOO" to "bar").parse("")
+        }
+    }
+
     @Test
     @JsName("shortHelp_extraction")
     fun `shortHelp extraction`() = forAll(
@@ -169,10 +196,11 @@ class CliktCommandTest {
     @Test
     @JsName("command_toString")
     fun `command toString`() {
-        class C : TestCommand(name="cmd") {
+        class C : TestCommand(name = "cmd") {
             init {
                 context { helpOptionNames = setOf() }
             }
+
             val opt by option("-o", "--option")
             val int by option().int()
             val args by argument().multiple()
@@ -211,6 +239,7 @@ class CliktCommandTest {
             init {
                 context { helpOptionNames = setOf() }
             }
+
             val g by G()
             val g2 by G2().cooccurring()
             val ge by mutuallyExclusiveOptions(
@@ -234,6 +263,7 @@ class CliktCommandTest {
             init {
                 context { helpOptionNames = setOf() }
             }
+
             val opt by option("-o", "--option")
             val args by argument().multiple()
             override fun run_() {

clikt-mordant/src/commonTest/kotlin/com/github/ajalt/clikt/parameters/EnvvarOptionsTest.kt

@@ -1,16 +1,16 @@
 package com.github.ajalt.clikt.parameters
 
-import com.github.ajalt.clikt.core.*
+import com.github.ajalt.clikt.core.BadParameterValue
+import com.github.ajalt.clikt.core.MutuallyExclusiveGroupException
+import com.github.ajalt.clikt.core.context
+import com.github.ajalt.clikt.core.subcommands
 import com.github.ajalt.clikt.parameters.groups.OptionGroup
 import com.github.ajalt.clikt.parameters.groups.cooccurring
 import com.github.ajalt.clikt.parameters.groups.mutuallyExclusiveOptions
 import com.github.ajalt.clikt.parameters.groups.single
 import com.github.ajalt.clikt.parameters.options.*
 import com.github.ajalt.clikt.parameters.types.int
-import com.github.ajalt.clikt.testing.TestCommand
-import com.github.ajalt.clikt.testing.TestSource
-import com.github.ajalt.clikt.testing.defaultLocalization
-import com.github.ajalt.clikt.testing.parse
+import com.github.ajalt.clikt.testing.*
 import io.kotest.assertions.throwables.shouldThrow
 import io.kotest.data.blocking.forAll
 import io.kotest.data.row
@@ -19,10 +19,6 @@ import kotlin.js.JsName
 import kotlin.test.Test
 
 class EnvvarOptionsTest {
-    private fun <T : CliktCommand> T.withEnv(vararg entries: Pair<String, String?>): T {
-        return context { readEnvvar = { entries.toMap()[it] } }
-    }
-
     @Test
     @JsName("explicit_envvar")
     fun `explicit envvar`() {

clikt-mordant/src/commonTest/kotlin/com/github/ajalt/clikt/testing/utils.kt

@@ -1,6 +1,8 @@
 package com.github.ajalt.clikt.testing
 
+import com.github.ajalt.clikt.core.CliktCommand
 import com.github.ajalt.clikt.core.UsageError
+import com.github.ajalt.clikt.core.context
 import com.github.ajalt.clikt.output.Localization
 import com.github.ajalt.clikt.output.ParameterFormatter
 
@@ -11,3 +13,7 @@ val Throwable.formattedMessage: String?
     ) ?: message
 
 internal val defaultLocalization = object : Localization {}
+
+internal fun <T : CliktCommand> T.withEnv(vararg entries: Pair<String, String?>): T {
+    return context { readEnvvar = { entries.toMap()[it] } }
+}

clikt/src/commonMain/kotlin/com/github/ajalt/clikt/parsers/ParserInternals.kt

@@ -2,6 +2,7 @@ package com.github.ajalt.clikt.parsers
 
 import com.github.ajalt.clikt.core.*
 import com.github.ajalt.clikt.parameters.options.Option
+import com.github.ajalt.clikt.parameters.options.hasEnvvarOrSourcedValue
 import com.github.ajalt.clikt.parameters.options.splitOptionPrefix
 
 internal fun <T : BaseCliktCommand<T>> parseArgv(
@@ -149,7 +150,9 @@ private class CommandParser<T : BaseCliktCommand<T>>(
     }
 
     private fun printHelpOnEmptyArgsIfNecessary(): Boolean {
-        if (i > tokens.lastIndex && command.printHelpOnEmptyArgs) {
+        if (i > tokens.lastIndex && command.printHelpOnEmptyArgs
+            && command._options.none { it.hasEnvvarOrSourcedValue(context, emptyList()) }
+        ) {
             errors += PrintHelpMessage(context, error = true)
             return true
         }