fix: Expected collections.iterable but got output: false positive

Resolves #317

CHANGES

@@ -23,6 +23,7 @@ Fixed:
 - Completion does not suggest top-level keywords in comments (see #178)
 - Suppress inspection doesn't work in some cases (see #313)
 - Don't show multiline string arg, may be comma is missing for sections with single arg (see #315)
+- Expected `collections.iterable` but got `output:` false positive (see #317)
 
 Version 0.8.0 build #0.8.0.214
 -------------

src/main/kotlin/com/jetbrains/snakecharm/lang/psi/types/SmkRuleLikeSectionArgsType.kt

@@ -10,7 +10,7 @@ import com.jetbrains.python.psi.*
 import com.jetbrains.python.psi.impl.ResolveResultList
 import com.jetbrains.python.psi.resolve.PyResolveContext
 import com.jetbrains.python.psi.resolve.RatedResolveResult
-import com.jetbrains.python.psi.types.PyType
+import com.jetbrains.python.psi.types.PyStructuralType
 import com.jetbrains.snakecharm.codeInsight.SnakemakeAPI.UNPACK_FUNCTION
 import com.jetbrains.snakecharm.codeInsight.completion.SmkCompletionUtil
 import com.jetbrains.snakecharm.codeInsight.resolve.SmkResolveUtil
@@ -20,9 +20,20 @@ import com.jetbrains.snakecharm.stringLanguage.lang.callSimpleName
 
 class SmkRuleLikeSectionArgsType(
         val section: SmkRuleOrCheckpointArgsSection
-) : PyType, SmkAvailableForSubscriptionType {
+) : PyStructuralType(
+    getSectionArgsNames(getSectionArgs(section)),
+    false
+), SmkAvailableForSubscriptionType {
+
+    companion object {
+        private fun getSectionArgs(section: SmkRuleOrCheckpointArgsSection)
+                = section.argumentList?.arguments
+        private fun getSectionArgsNames(args: Array<PyExpression>?)
+                = args?.filterIsInstance<PyKeywordArgument>()?.mapNotNull { it.name }?.toSet() ?: emptySet()
+    }
 
     private val typeName: String = section.sectionKeyword?.let { "$it:" } ?: "section"
+    private val sectionArgs: Array<out PyExpression>? = getSectionArgs(section)
 
     override fun getName() = typeName
 
@@ -42,15 +53,13 @@ class SmkRuleLikeSectionArgsType(
             return emptyList()
         }
 
-        val args = getSectionArgs()
-
         @Suppress("FoldInitializerAndIfToElvis")
-        if (args == null) {
+        if (sectionArgs == null) {
             return emptyList()
         }
 
         val resolveResult = ResolveResultList()
-        args.filterIsInstance<PyKeywordArgument>()
+        sectionArgs.filterIsInstance<PyKeywordArgument>()
                 .filter { it.name == name }
                 .forEach {
                     resolveResult.poke(it, SmkResolveUtil.RATE_NORMAL)
@@ -65,20 +74,16 @@ class SmkRuleLikeSectionArgsType(
             direction: AccessDirection,
             resolveContext: PyResolveContext
     ): List<RatedResolveResult> {
-        val args = getSectionArgs()
-
-        if (args != null && isSimpleArgsList(args)) {
+        if (sectionArgs != null && isSimpleArgsList(sectionArgs)) {
             val resolveResult = ResolveResultList()
-            if (idx in args.indices) {
-                resolveResult.poke(args[idx], SmkResolveUtil.RATE_NORMAL)
+            if (idx in sectionArgs.indices) {
+                resolveResult.poke(sectionArgs[idx], SmkResolveUtil.RATE_NORMAL)
             }
             return resolveResult
         }
         return emptyList()
     }
 
-    private fun getSectionArgs(): Array<out PyExpression>? = section.argumentList?.arguments
-
     override fun getCompletionVariants(
             completionPrefix: String?,
             location: PsiElement,
@@ -106,20 +111,19 @@ class SmkRuleLikeSectionArgsType(
         }
 
         val results = arrayListOf<LookupElementBuilder>()
-        val args = getSectionArgs()
 
         @Suppress("FoldInitializerAndIfToElvis")
-        if (args == null) {
+        if (sectionArgs == null) {
             return emptyList<LookupElementBuilder>() to priority
         }
 
         val sectionKeyword = section.sectionKeyword
         val typeText = "$sectionKeyword section key"
-        args.filterIsInstance<PyKeywordArgument>().forEach {
+        attributeNames.forEach { name ->
             val item = LookupElementBuilder
-                    .create(it.name!!)
+                    .create(name)
                     .withTypeText(typeText)
-                    .withIcon(PlatformIcons.PARAMETER_ICON)
+                    .withIcon(PlatformIcons.FIELD_ICON)
             results.add(item)
         }
 
@@ -134,13 +138,11 @@ class SmkRuleLikeSectionArgsType(
             return 0
         }
 
-        val args = getSectionArgs()
-
-        if (args == null || !isSimpleArgsList(args)) {
+        if (sectionArgs == null || !isSimpleArgsList(sectionArgs)) {
             return 0
         }
 
-        return args.size
+        return sectionArgs.size
     }
 
     private fun isSimpleArgsList(args: Array<out PyExpression>): Boolean {

src/test/resources/features/highlighting/inspections/py_type_checker_inspection.feature

@@ -0,0 +1,31 @@
+Feature: Fixes for PyTypeCheckerInspection related false positives
+  Scenario Outline: Args Section type is iterable
+    Given a snakemake project
+    Given I open a file "foo.smk" with text
+    """
+    rule rule_317_1:
+        output: "d"
+
+    <rule_like> rule_317_2:
+        input: expand(
+            [s for s in rules.rule_317_1.output],
+            [s for s in 1],
+            key="val"
+        )
+        output: "out.txt"
+        run:
+            with open(output[0], 'w') as out:
+                for p in input:
+                    print(p, file=out)
+    """
+    And PyTypeCheckerInspection inspection is enabled
+    # warning only for `1`, not for `rules.rule_317_1.output` and not for `for p in input`
+    Then I expect inspection warning on <1> in <[s for s in 1]> with message
+    """
+    Expected 'collections.Iterable', got 'int' instead
+    """
+    When I check highlighting warnings
+    Examples:
+      | rule_like   |
+      | rule        |
+      | checkpoint  |