refactor(deps): inline decamelize dependency

package.json

@@ -95,7 +95,6 @@
     "url": "https://github.com/salsita/node-pg-migrate.git"
   },
   "dependencies": {
-    "decamelize": "^5.0.0",
     "mkdirp": "~1.0.0",
     "yargs": "~17.7.0"
   },

src/utils/createSchemalize.ts

@@ -1,6 +1,7 @@
-import decamelize from 'decamelize';
-import { identity, quote } from '.';
 import type { Name } from '../operations/generalTypes';
+import { decamelize } from './decamelize';
+import { identity } from './identity';
+import { quote } from './quote';
 
 /** @deprecated Use createSchemalize(options) instead. */
 export function createSchemalize(

src/utils/decamelize.ts

@@ -0,0 +1,36 @@
+// Simplified copy of https://github.com/sindresorhus/decamelize/blob/5deb8c5b88c3dbc93ef0d68faa0fc45cf98cad9d/index.js
+const REPLACEMENT = '$1_$2';
+
+/**
+ * Convert a string into a decamelize lowercased one.
+ *
+ * @example
+ * unicornsAndRainbows → unicorns_and_rainbows
+ * myURLString → my_url_string
+ *
+ * @param text The string to decamelize.
+ * @returns The decamelized string.
+ */
+export function decamelize(text: string): string {
+  // Checking the second character is done later on. Therefore process shorter strings here.
+  if (text.length < 2) {
+    return text.toLowerCase();
+  }
+
+  // Split lowercase sequences followed by uppercase character.
+  // `dataForUSACounties` → `data_For_USACounties`
+  // `myURLstring → `my_URLstring`
+  const decamelized = text.replace(
+    /([\p{Lowercase_Letter}\d])(\p{Uppercase_Letter})/gu,
+    REPLACEMENT
+  );
+
+  // Split multiple uppercase characters followed by one or more lowercase characters.
+  // `my_URLstring` → `my_ur_lstring`
+  return decamelized
+    .replace(
+      /(\p{Uppercase_Letter})(\p{Uppercase_Letter}\p{Lowercase_Letter}+)/gu,
+      REPLACEMENT
+    )
+    .toLowerCase();
+}

src/utils/index.ts

@@ -1,5 +1,6 @@
 export { createSchemalize } from './createSchemalize';
 export { createTransformer } from './createTransformer';
+export { decamelize } from './decamelize';
 export { escapeValue } from './escapeValue';
 export { formatLines } from './formatLines';
 export { formatParams } from './formatParams';

test/utils/decamelize.spec.ts

@@ -0,0 +1,30 @@
+import { describe, expect, it } from 'vitest';
+import { decamelize } from '../../src/utils';
+
+describe('utils', () => {
+  describe('decamelize', () => {
+    it.each([
+      ['', ''],
+      ['A', 'a'],
+      ['A B', 'a b'],
+      ['a2b', 'a2b'],
+      ['A2B', 'a2_b'],
+      ['_A2B', '_a2_b'],
+      ['myURLstring', 'my_ur_lstring'],
+      ['unicornsAndRainbows', 'unicorns_and_rainbows'],
+      ['UNICORNS AND RAINBOWS', 'unicorns and rainbows'],
+      ['unicorns-and-rainbows', 'unicorns-and-rainbows'],
+      ['thisIsATest', 'this_is_a_test'],
+      ['myURLString', 'my_url_string'],
+      ['URLString', 'url_string'],
+      ['StringURL', 'string_url'],
+      ['testGUILabel', 'test_gui_label'],
+      ['CAPLOCKED1', 'caplocked1'],
+      ['my_URL_string', 'my_url_string'],
+    ])('should handle string %s', (input, expected) => {
+      const actual = decamelize(input);
+
+      expect(actual).toBe(expected);
+    });
+  });
+});