fix: auto import for really long names

mtags-shared/src/main/scala/scala/meta/internal/metals/Fuzzy.scala

@@ -322,11 +322,17 @@ class Fuzzy {
       symbol: String,
       hasher: StringBloomFilter
   ): Unit = {
+    var allUpper = List.empty[String]
+    val upper = new StringBuilder()
+    def flushUpper() =
+      if (upper.nonEmpty) {
+        allUpper = upper.result() :: allUpper
+        upper.clear()
+      }
     if (symbol.endsWith("$sp.class")) return
     hasher.reset()
     var i = 0
     var delimiter = i
-    val upper = new StringBuilder()
     var symbolicDelimiter = i
     val N = lastIndex(symbol)
     while (i < N) {
@@ -336,6 +342,7 @@ class Fuzzy {
           hasher.reset()
           delimiter = i + 1
           symbolicDelimiter = delimiter
+          flushUpper()
         case _ =>
           if (ch.isUpper) {
             delimiter = i
@@ -365,8 +372,9 @@ class Fuzzy {
         idx += 1
       }
     }
+    flushUpper()
     TrigramSubstrings.foreach(
-      upper.toString,
+      allUpper,
       trigram => hasher.putCharSequence(trigram)
     )
   }
@@ -411,8 +419,14 @@ class Fuzzy {
     else if (query.length() < PrefixSearchLimit && !isShortQueryRetry)
       List(PrefixCharSequence(query))
     else {
-      val result = mutable.Set.empty[CharSequence]
+      var allUpper = List.empty[String]
       val upper = new StringBuilder
+      def flushUpper() =
+        if (upper.nonEmpty) {
+          allUpper = upper.result() :: allUpper
+          upper.clear()
+        }
+      val result = mutable.Set.empty[CharSequence]
       var i = 0
       var border = 0
       while (i < query.length) {
@@ -421,6 +435,7 @@ class Fuzzy {
           case '.' | '/' | '#' | '$' =>
             result.add(new ZeroCopySubSequence(query, border, i))
             border = i + 1
+            flushUpper()
           case _ =>
             if (ch.isUpper) {
               if (border != i) {
@@ -438,8 +453,9 @@ class Fuzzy {
         case _ =>
           result.add(new ZeroCopySubSequence(query, border, query.length))
       }
+      flushUpper()
       if (includeTrigrams) {
-        TrigramSubstrings.foreach(upper.toString, trigram => result += trigram)
+        TrigramSubstrings.foreach(allUpper, trigram => result += trigram)
       }
       result
     }

mtags-shared/src/main/scala/scala/meta/internal/metals/TrigramSubstrings.scala

@@ -12,29 +12,62 @@ object TrigramSubstrings {
    * }}}
    */
   val DefaultMaxTrigrams = 250
+  type StartFromZero = Boolean
 
   /**
    * Iterate over all possible substrings of length 3 for the given string.
    */
   def foreach(
-      inString: String,
+      inputs: List[String],
       f: String => Unit,
       maxResults: Int = DefaultMaxTrigrams
   ): Unit = {
-    val string = inString.reverse
-    val N = string.length
-    val arr = new Array[Char](3)
+    val N = inputs.length
     var max = maxResults
     def isNotDone = max > 0
     var i = 0
     while (i < N && isNotDone) {
-      var j = i + 1
+      var j = i
       while (j < N && isNotDone) {
-        var k = j + 1
+        var k = j
         while (k < N && isNotDone) {
-          arr(2) = string.charAt(i)
-          arr(1) = string.charAt(j)
-          arr(0) = string.charAt(k)
+          max = fromLists(
+            inputs(k),
+            (inputs(j), j != k),
+            (inputs(i), i != j),
+            f,
+            max
+          )
+          k += 1
+        }
+        j += 1
+      }
+      i += 1
+    }
+  }
+
+  private def fromLists(
+      input1: String,
+      input2: (String, StartFromZero),
+      input3: (String, StartFromZero),
+      f: String => Unit,
+      maxResults: Int
+  ): Int = {
+    val N1 = input1.length
+    val N2 = input2._1.length
+    val N3 = input3._1.length
+    val arr = new Array[Char](3)
+    var max = maxResults
+    def isNotDone = max > 0
+    var i = 0
+    while (i < N1 && isNotDone) {
+      var j = if (input2._2) 0 else i + 1
+      while (j < N2 && isNotDone) {
+        var k = if (input3._2) 0 else j + 1
+        while (k < N3 && isNotDone) {
+          arr(0) = input1.charAt(i)
+          arr(1) = input2._1.charAt(j)
+          arr(2) = input3._1.charAt(k)
           f(new String(arr))
           max -= 1
           k += 1
@@ -43,14 +76,15 @@ object TrigramSubstrings {
       }
       i += 1
     }
+    max
   }
 
   /**
    * Returns all possible substrings of length 3 for the given string.
    */
-  def seq(string: String): ArrayBuffer[String] = {
+  def seq(inputs: List[String]): ArrayBuffer[String] = {
     val buf = ArrayBuffer.empty[String]
-    foreach(string, trigram => buf += trigram)
+    foreach(inputs.reverse, trigram => buf += trigram)
     buf
   }
 

tests/slow/src/test/scala/tests/feature/ImportMissingSymbolCrossLspSuite.scala

@@ -194,7 +194,40 @@ class ImportMissingSymbolCrossLspSuite
        |  }
        |}
        |""".stripMargin,
-    scalaVersion = "3.3.3",
+    scalaVersion = V.scala3,
+  )
+
+  check(
+    "i6475-2",
+    """|package com.randomMetalsTest.app.latestCommentByItem.domain.projection.latestCommentByItemView
+       |package subscriber {
+       |  class DeleteLatestCommentByItemViewOnLatestCommentByItemDeleted
+       |}
+       |package a {
+       |  object O {
+       |    val g: <<DeleteLatestCommentByItemViewOnLatestCommentByItemDeleted>> = ???
+       |  }
+       |}
+       |""".stripMargin,
+    s"""|${ImportMissingSymbol.title(
+         "DeleteLatestCommentByItemViewOnLatestCommentByItemDeleted",
+         "com.randomMetalsTest.app.latestCommentByItem.domain.projection.latestCommentByItemView.subscriber",
+       )}
+        |${CreateNewSymbol.title("DeleteLatestCommentByItemViewOnLatestCommentByItemDeleted")}
+        |""".stripMargin,
+    """|package com.randomMetalsTest.app.latestCommentByItem.domain.projection.latestCommentByItemView
+       |
+       |import com.randomMetalsTest.app.latestCommentByItem.domain.projection.latestCommentByItemView.subscriber.DeleteLatestCommentByItemViewOnLatestCommentByItemDeleted
+       |package subscriber {
+       |  class DeleteLatestCommentByItemViewOnLatestCommentByItemDeleted
+       |}
+       |package a {
+       |  object O {
+       |    val g: DeleteLatestCommentByItemViewOnLatestCommentByItemDeleted = ???
+       |  }
+       |}
+       |""".stripMargin,
+    scalaVersion = V.scala3,
   )
 
 }

tests/unit/src/test/scala/tests/TrigramSubstringsSuite.scala

@@ -9,7 +9,8 @@ class TrigramSubstringsSuite extends BaseSuite {
       loc: Location
   ): Unit = {
     test(original) {
-      val obtained = TrigramSubstrings.seq(original).mkString("\n")
+      val obtained =
+        TrigramSubstrings.seq(original.split('.').toList).mkString("\n")
       assertNoDiff(obtained, expected)
     }
   }
@@ -23,13 +24,20 @@ class TrigramSubstringsSuite extends BaseSuite {
       assertNoDiff(obtained, expected)
     }
   }
+
   check(
-    "abcd",
+    "a.bcde",
     """
       |bcd
-      |acd
-      |abd
+      |bce
+      |bde
+      |cde
       |abc
+      |abd
+      |abe
+      |acd
+      |ace
+      |ade
       |""".stripMargin,
   )