LAB-29: don't report history position for new files

GitOrigin-RevId: 7f563a9fbda277ea65d2b13e9ac4c3a460479391

plugins/filePrediction/src/com/intellij/filePrediction/history/FileHistoryManager.kt

@@ -1,6 +1,6 @@
 package com.intellij.filePrediction.history
 
-data class FileHistoryFeatures(val position: Int, val uniGram: NextFileProbability, val biGram: NextFileProbability)
+data class FileHistoryFeatures(val position: Int?, val uniGram: NextFileProbability, val biGram: NextFileProbability)
 
 data class NextFileProbability(
   val mle: Double, val minMle: Double, val maxMle: Double, val mleToMin: Double, val mleToMax: Double
@@ -67,7 +67,7 @@ class FileHistoryManager(private var state: FilePredictionHistoryState, private
 
     val fileWasPreviouslyOpened = index in 0 until size
     val entry = if (fileWasPreviouslyOpened) state.recentFiles[index] else null
-    val position = if (fileWasPreviouslyOpened) size - index - 1 else -1
+    val position = if (fileWasPreviouslyOpened) size - index - 1 else null
     val uniGram = helper.calculateUniGramProb(state.root, entry?.code)
     val biGram = helper.calculateBiGramProb(state.root, entry?.code, state.prevFile)
     return FileHistoryFeatures(position, uniGram, biGram)

plugins/filePrediction/src/com/intellij/filePrediction/history/FilePredictionHistoryFeatures.kt

@@ -16,7 +16,9 @@ internal class FilePredictionHistoryFeatures: FilePredictionFeatureProvider {
     result["size"] = numerical(history.size())
 
     val (position, uniGram, biGram) = history.calcHistoryFeatures(newFile.url)
-    result["position"] = numerical(position)
+    if (position != null) {
+      result["position"] = numerical(position)
+    }
     addNGramFeatures(uniGram, "uni", result)
     addNGramFeatures(biGram, "bi", result)
     return result

plugins/filePrediction/test/com/intellij/filePrediction/features/FilePredictionFeaturesTest.kt

@@ -40,7 +40,6 @@ class FilePredictionFeaturesTest : CodeInsightFixtureTestCase<ModuleFixtureBuild
       "path_prefix",
       "relative_path_prefix",
       "history_size",
-      "history_position",
       "history_uni_mle",
       "history_bi_mle"
     )

plugins/filePrediction/test/com/intellij/filePrediction/features/history/FilePredictionHistoryFeaturesTest.kt

@@ -5,7 +5,7 @@ import com.intellij.filePrediction.history.FilePredictionHistoryState
 
 class FilePredictionHistoryFeaturesTest : FilePredictionHistoryBaseTest() {
 
-  private fun doTest(openedFiles: List<String>, size: Int, vararg expected: Pair<String, Int>) {
+  private fun doTest(openedFiles: List<String>, size: Int, vararg expected: Pair<String, Int?>) {
     doTestInternal(openedFiles, size, 5) { manager ->
       expected.forEach { assertEquals(it.second, manager.calcHistoryFeatures(it.first).position) }
     }
@@ -25,11 +25,11 @@ class FilePredictionHistoryFeaturesTest : FilePredictionHistoryBaseTest() {
   }
 
   fun `test position of the file without history`() {
-    doTest(listOf(), 0, "file://a" to -1)
+    doTest(listOf(), 0, "file://a" to null)
   }
 
   fun `test position of the new file`() {
-    doTest(listOf("file://a"), 1, "file://b" to -1)
+    doTest(listOf("file://a"), 1, "file://b" to null)
   }
 
   fun `test position of the prev file`() {