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node_modules/graphql/jsutils/suggestionList.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = suggestionList;
+
+/**
+ * Given an invalid input string and a list of valid options, returns a filtered
+ * list of valid options sorted based on their similarity with the input.
+ */
+function suggestionList(input, options) {
+  var optionsByDistance = Object.create(null);
+  var inputThreshold = input.length / 2;
+
+  for (var _i2 = 0; _i2 < options.length; _i2++) {
+    var option = options[_i2];
+    var distance = lexicalDistance(input, option);
+    var threshold = Math.max(inputThreshold, option.length / 2, 1);
+
+    if (distance <= threshold) {
+      optionsByDistance[option] = distance;
+    }
+  }
+
+  return Object.keys(optionsByDistance).sort(function (a, b) {
+    return optionsByDistance[a] - optionsByDistance[b];
+  });
+}
+/**
+ * Computes the lexical distance between strings A and B.
+ *
+ * The "distance" between two strings is given by counting the minimum number
+ * of edits needed to transform string A into string B. An edit can be an
+ * insertion, deletion, or substitution of a single character, or a swap of two
+ * adjacent characters.
+ *
+ * Includes a custom alteration from Damerau-Levenshtein to treat case changes
+ * as a single edit which helps identify mis-cased values with an edit distance
+ * of 1.
+ *
+ * This distance can be useful for detecting typos in input or sorting
+ *
+ * @param {string} a
+ * @param {string} b
+ * @return {int} distance in number of edits
+ */
+
+
+function lexicalDistance(aStr, bStr) {
+  if (aStr === bStr) {
+    return 0;
+  }
+
+  var d = [];
+  var a = aStr.toLowerCase();
+  var b = bStr.toLowerCase();
+  var aLength = a.length;
+  var bLength = b.length; // Any case change counts as a single edit
+
+  if (a === b) {
+    return 1;
+  }
+
+  for (var i = 0; i <= aLength; i++) {
+    d[i] = [i];
+  }
+
+  for (var j = 1; j <= bLength; j++) {
+    d[0][j] = j;
+  }
+
+  for (var _i3 = 1; _i3 <= aLength; _i3++) {
+    for (var _j = 1; _j <= bLength; _j++) {
+      var cost = a[_i3 - 1] === b[_j - 1] ? 0 : 1;
+      d[_i3][_j] = Math.min(d[_i3 - 1][_j] + 1, d[_i3][_j - 1] + 1, d[_i3 - 1][_j - 1] + cost);
+
+      if (_i3 > 1 && _j > 1 && a[_i3 - 1] === b[_j - 2] && a[_i3 - 2] === b[_j - 1]) {
+        d[_i3][_j] = Math.min(d[_i3][_j], d[_i3 - 2][_j - 2] + cost);
+      }
+    }
+  }
+
+  return d[aLength][bLength];
+}