routie dev init since i didn't adhere to any proper guidance up until now

frontend/node_modules/eslint-plugin-perfectionist/dist/utils/get-newlines-between-errors.js

@@ -0,0 +1,82 @@
+import { getNewlinesBetweenOption } from './get-newlines-between-option.js'
+import { getLinesBetween } from './get-lines-between.js'
+/**
+ * Checks if the newlines between two nodes match the required configuration.
+ *
+ * Validates the number of empty lines between two nodes against the expected
+ * newlines based on their group indices and configuration. Generates
+ * appropriate error messages when the actual newlines don't match the
+ * requirement.
+ *
+ * The function returns no errors if:
+ *
+ * - The left node's group index is greater than the right's (wrong order)
+ * - The nodes are in different partitions
+ * - The newlines configuration is set to 'ignore'
+ * - The actual newlines match the expected newlines.
+ *
+ * @example
+ *
+ * ```ts
+ * // Configuration requires 1 newline between different groups
+ * const errors = getNewlinesBetweenErrors({
+ *   options: { newlinesBetween: 1, groups: ['imports', 'types'] },
+ *   leftGroupIndex: 0, // imports group
+ *   rightGroupIndex: 1, // types group
+ *   left: importNode,
+ *   right: typeNode,
+ *   sourceCode,
+ *   missedSpacingError: 'missedNewline',
+ *   extraSpacingError: 'extraNewline',
+ * })
+ * // If no newline between nodes: Returns ['missedNewline']
+ * // If 2+ newlines between nodes: Returns ['extraNewline']
+ * // If exactly 1 newline: Returns []
+ * ```
+ *
+ * @template MessageIds - Type of error message identifiers.
+ * @template T - Type of the sorting node.
+ * @param params - Parameters for newline checking.
+ * @returns Array of error message IDs (empty if no errors).
+ */
+function getNewlinesBetweenErrors({
+  newlinesBetweenValueGetter,
+  missedSpacingError,
+  extraSpacingError,
+  rightGroupIndex,
+  leftGroupIndex,
+  sourceCode,
+  options,
+  right,
+  left,
+}) {
+  if (
+    leftGroupIndex > rightGroupIndex ||
+    left.partitionId !== right.partitionId
+  ) {
+    return []
+  }
+  let newlinesBetween = getNewlinesBetweenOption({
+    nextNodeGroupIndex: rightGroupIndex,
+    nodeGroupIndex: leftGroupIndex,
+    options,
+  })
+  newlinesBetween =
+    newlinesBetweenValueGetter?.({
+      computedNewlinesBetween: newlinesBetween,
+      right,
+      left,
+    }) ?? newlinesBetween
+  if (newlinesBetween === 'ignore') {
+    return []
+  }
+  let numberOfEmptyLinesBetween = getLinesBetween(sourceCode, left, right)
+  if (numberOfEmptyLinesBetween < newlinesBetween) {
+    return [missedSpacingError]
+  }
+  if (numberOfEmptyLinesBetween > newlinesBetween) {
+    return [extraSpacingError]
+  }
+  return []
+}
+export { getNewlinesBetweenErrors }