Support escaping commas in extra flags (#443)

* Support escaping commas in extra flags

Author: petertrr

save-common/src/commonMain/kotlin/com/saveourtool/save/core/plugin/ExtraFlagsExtractor.kt

@@ -29,7 +29,8 @@ class ExtraFlagsExtractor(private val generalConfig: GeneralConfig,
      * @return [ExtraFlags] or null if no match occurred
      */
     internal fun extractExtraFlagsFrom(line: String) = line
-        .split(",", ", ")
+        .splitByNonEscaped(',')
+        .map { it.replace("\\,", ",") }
         .associate { part ->
             val pair = part.split("=", limit = 2).map {
                 it.replace("\\=", "=")
@@ -69,6 +70,29 @@ internal fun List<String>.filterAndJoinBy(regex: Regex, ending: Char): List<Stri
         }
     }
 
+/**
+ * Split [this] string by [delimiter] unless it's prepended by `\`.
+ *
+ * @param delimiter
+ * @return list of string parts
+ */
+@Suppress("IDENTIFIER_LENGTH")
+internal fun String.splitByNonEscaped(delimiter: Char): List<String> {
+    val indicesToSplit = mapIndexed { index, c -> index to c }
+        .filter { (index, c) ->
+            c == delimiter && (index == 0 || get(index - 1) != '\\')
+        }
+        .map { (index, _) -> index }
+    val result: MutableList<String> = mutableListOf()
+    var currentOffset = 0
+    indicesToSplit.forEach {
+        result.add(substring(currentOffset, it))
+        currentOffset = it + 1
+    }
+    result.add(substring(currentOffset, length))
+    return result
+}
+
 /**
  * Substitute placeholders in `this.execFlags` with values from provided arguments
  *

save-common/src/commonNonJsTest/kotlin/com/saveourtool/save/core/ExtraFlagsExtractorTest.kt

@@ -5,12 +5,17 @@ import com.saveourtool.save.core.plugin.ExtraFlagsExtractor
 import com.saveourtool.save.core.plugin.GeneralConfig
 import com.saveourtool.save.core.plugin.filterAndJoinBy
 import com.saveourtool.save.core.plugin.resolvePlaceholdersFrom
+import com.saveourtool.save.core.plugin.splitByNonEscaped
 
 import okio.fakefilesystem.FakeFileSystem
 
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
+@Suppress(
+    "TOO_LONG_FUNCTION",
+    "WRONG_INDENTATION",  // issue in diktat
+)
 class ExtraFlagsExtractorTest {
     @Test
     fun `basic test`() {
@@ -26,6 +31,9 @@ class ExtraFlagsExtractorTest {
             "Unparseable nonsense" to ExtraFlags.empty,
             "args1=--flag --opt,args2=-debug --flag2" to ExtraFlags("--flag --opt", "-debug --flag2"),
             "args1=--flag\\=value,args2=--foo=bar" to ExtraFlags("--flag=value", "--foo=bar"),
+            "args1=option1\\,option2,args2=option3\\,option4" to ExtraFlags("option1,option2", "option3,option4"),
+            "args1=option1\\,option2" to ExtraFlags("option1,option2", ""),
+            "args2=option3\\,option4" to ExtraFlags("", "option3,option4"),
         )
             .forEach { (line, extraFlags) ->
                 assertEquals(extraFlags, extraFlagsExtractor.extractExtraFlagsFrom(line))
@@ -105,6 +113,52 @@ class ExtraFlagsExtractorTest {
                 "another-cmd --flag"
             )
         )
+
+        checkMultilineDirectives(
+            Regex("""// RUN: (.*([^\\]=)?.*)\\?"""),
+            listOf(
+                "// RUN: command --flag=option\\,\\",
+                "// RUN: another-option --another-flag",
+                "// RUN: another-cmd\\=\\",
+                "// RUN: --flag=option\\,another-option",
+            ),
+            listOf(
+                "command --flag=option\\,another-option --another-flag",
+                "another-cmd\\=--flag=option\\,another-option"
+            )
+        )
+    }
+
+    @Test
+    fun `test for splitByNonEscaped`() {
+        assertEquals(
+            listOf("this string\\, not split"),
+            "this string\\, not split".splitByNonEscaped(','),
+        )
+        assertEquals(
+            listOf("this string", " but split"),
+            "this string, but split".splitByNonEscaped(','),
+        )
+        assertEquals(
+            listOf("this string\\, not split", " but here - it's split"),
+            "this string\\, not split, but here - it's split".splitByNonEscaped(','),
+        )
+        assertEquals(
+            listOf("", ""),
+            ",".splitByNonEscaped(','),
+        )
+        assertEquals(
+            listOf("", "text"),
+            ",text".splitByNonEscaped(','),
+        )
+        assertEquals(
+            listOf("\\,"),
+            "\\,".splitByNonEscaped(','),
+        )
+        assertEquals(
+            listOf("\\,text"),
+            "\\,text".splitByNonEscaped(','),
+        )
     }
 
     private fun checkMultilineDirectives(