From bed9a6178b56523641cede5290f46b994e4ba037 Mon Sep 17 00:00:00 2001
From: Mark Punzalan <markpun@google.com>
Date: Sat, 11 Sep 2021 07:20:20 +0000
Subject: [PATCH] KotlinHighLevelFunctionParameterInfoHandler: Fix computation
 of "named mode".

GitOrigin-RevId: 7fbc6e06dfea4554b7b92629b565bffb7a276289
---
 ...inHighLevelFunctionParameterInfoHandler.kt | 27 +++++++++----------
 .../parameterInfo/functionCall/NotGreen.kt    |  2 --
 2 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/plugins/kotlin/fir/src/org/jetbrains/kotlin/idea/parameterInfo/KotlinHighLevelFunctionParameterInfoHandler.kt b/plugins/kotlin/fir/src/org/jetbrains/kotlin/idea/parameterInfo/KotlinHighLevelFunctionParameterInfoHandler.kt
index f9f5d4e117bb..b508f5a09f48 100644
--- a/plugins/kotlin/fir/src/org/jetbrains/kotlin/idea/parameterInfo/KotlinHighLevelFunctionParameterInfoHandler.kt
+++ b/plugins/kotlin/fir/src/org/jetbrains/kotlin/idea/parameterInfo/KotlinHighLevelFunctionParameterInfoHandler.kt
@@ -322,6 +322,8 @@ abstract class KotlinHighLevelParameterInfoWithCallHandlerBase<TArgumentList : K
      *    See NamedParameter4.kt test.
      * 3. When the named argument IS in its own position, and LanguageFeature.MixedNamedArgumentsInTheirOwnPosition is DISABLED, then
      *    `namedMode = true` as described above. See MixedNamedArguments2.kt test.
+     * 4. `isDisabledBeforeHighlight = true` is used to separate used parameters (before the highlight) from unused parameters, if there
+     *    are any unused parameters.
      *
      * The logic for highlighting a parameter (i.e., by setting `highlight(Start|End)Offset`) is as follows:
      * 1. A parameter is highlighted when the cursor is on the corresponding argument in the candidate's mapping.
@@ -390,9 +392,8 @@ abstract class KotlinHighLevelParameterInfoWithCallHandlerBase<TArgumentList : K
                     if (length > 0) {
                         append(", ")
                         if (markUsedUnusedParameterBorder) {
-                            // TODO: This matches FE 1.0 plugin behavior, but consider removing "disable before highlight".
-                            // It's odd that we disable the used parameters, even though they might match. See NamedParameter3.kt test:
-                            // `y = false` matches, and we disable it even though the next argument could match too (e.g., `x = `).
+                            // This is used to "disable" the used parameters, when in "named mode" and there are more unused parameters.
+                            // See NamedParameter3.kt test. Disabling them gives a visual cue that they are already used.
 
                             // Highlight the space after the comma; highlighted text needs to be at least one character long
                             highlightStartOffset = length - 1
@@ -422,6 +423,15 @@ abstract class KotlinHighLevelParameterInfoWithCallHandlerBase<TArgumentList : K
                 if (valueArguments != null) {
                     for (valueArgument in valueArguments) {
                         val parameterIndex = argumentToParameterIndex[valueArgument.getArgumentExpression()]
+                        if (valueArgument.isNamed() &&
+                            !(supportsMixedNamedArgumentsInTheirOwnPosition && parameterIndex != null && parameterIndex == argumentIndex)
+                        ) {
+                            // "Named mode" (all arguments should be named) begins when there is a named argument NOT in their own position
+                            // or a named argument is unmapped (i.e., non-existent name),
+                            // or named arguments in their own position is not supported.
+                            namedMode = true
+                        }
+
                         if (parameterIndex == null) {
                             hasUnmappedArgument = true
                             if (argumentIndex < currentArgumentIndex) {
@@ -432,14 +442,6 @@ abstract class KotlinHighLevelParameterInfoWithCallHandlerBase<TArgumentList : K
                         }
                         if (!usedParameterIndices.add(parameterIndex)) continue
 
-                        if (valueArgument.isNamed() &&
-                            !(supportsMixedNamedArgumentsInTheirOwnPosition && parameterIndex == argumentIndex)
-                        ) {
-                            // "Named mode" (all arguments should be named) begins when there is a named argument NOT in their own position
-                            // or named arguments in their own position is not supported.
-                            namedMode = true
-                        }
-
                         val shouldHighlight = parameterIndex == highlightParameterIndex
                         appendParameter(parameterIndex, shouldHighlight, valueArgument.isNamed())
                     }
@@ -464,9 +466,6 @@ abstract class KotlinHighLevelParameterInfoWithCallHandlerBase<TArgumentList : K
 
                 for (parameterIndex in 0 until valueParameterCount) {
                     if (parameterIndex !in usedParameterIndices) {
-                        if (argumentIndex != parameterIndex) {
-                            namedMode = true
-                        }
                         // Highlight the first unused parameter if it is in the correct position
                         val shouldHighlight = !namedMode && highlightStartOffset == -1
                         appendParameter(
diff --git a/plugins/kotlin/idea/tests/testData/parameterInfo/functionCall/NotGreen.kt b/plugins/kotlin/idea/tests/testData/parameterInfo/functionCall/NotGreen.kt
index fbaeec0ec971..bca07c182ec0 100644
--- a/plugins/kotlin/idea/tests/testData/parameterInfo/functionCall/NotGreen.kt
+++ b/plugins/kotlin/idea/tests/testData/parameterInfo/functionCall/NotGreen.kt
@@ -1,5 +1,3 @@
-// IGNORE_FIR
-// TODO: Fails because no argument mapping is available when there are multiple ambiguous candidates
 open class A(x: Int) {
     fun m(x: Int, y: Boolean) = 2
     fun m(x: Int) = 1