Clean up ignore files during migration (#94)

This should leave repos migrated from `seek-module-toolkit` and pre-#58
ignore files in a better state instead of littering old patterns
everywhere.

.changeset/spicy-jeans-remember.md

@@ -0,0 +1,5 @@
+---
+'skuba': patch
+---
+
+**configure:** Clean up ignore files during migration

src/cli/configure/processing/__snapshots__/ignoreFile.test.ts.snap

@@ -2,14 +2,14 @@
 
 exports[`mergeWithIgnoreFile empty provided 1`] = `
 "# managed by skuba
-node_modules
+node_modules*/
 # end managed by skuba
 "
 `;
 
 exports[`mergeWithIgnoreFile identical 1`] = `
 "# managed by skuba
-node_modules
+node_modules*/
 # end managed by skuba
 "
 `;
@@ -19,17 +19,37 @@ exports[`mergeWithIgnoreFile provided with managed section and additional lines
 .vscode
 
 # managed by skuba
-node_modules
+node_modules*/
 # end managed by skuba
 
 .DS_Store
 node_modules
 "
 `;
 
+exports[`mergeWithIgnoreFile provided with managed section and fully superseded config 1`] = `
+"# managed by skuba
+node_modules*/
+.DS_Store
+# end managed by skuba
+"
+`;
+
+exports[`mergeWithIgnoreFile provided with managed section and partially superseded config 1`] = `
+"# managed by skuba
+node_modules*/
+.DS_Store
+# end managed by skuba
+
+system32
+
+*.zip
+"
+`;
+
 exports[`mergeWithIgnoreFile provided with no managed section 1`] = `
 "# managed by skuba
-node_modules
+node_modules*/
 # end managed by skuba
 
 .DS_Store
@@ -38,7 +58,7 @@ node_modules
 
 exports[`mergeWithIgnoreFile provided with outdated managed section 1`] = `
 "# managed by skuba
-node_modules
+node_modules*/
 .DS_Store
 # end managed by skuba
 "
@@ -49,7 +69,7 @@ exports[`mergeWithIgnoreFile provided with outdated managed section and addition
 .vscode
 
 # managed by skuba
-node_modules
+node_modules*/
 .DS_Store
 # end managed by skuba
 

src/cli/configure/processing/ignoreFile.test.ts

@@ -1,15 +1,38 @@
-import { mergeWithIgnoreFile } from './ignoreFile';
+import { generateSimpleVariants, mergeWithIgnoreFile } from './ignoreFile';
+
+describe('generateSimpleVariants', () => {
+  it.each([
+    ['variant path', ['/lib*/'], ['/lib*/', '/lib/', '/lib', 'lib/', 'lib']],
+    ['non-variant path', ['lib'], ['lib']],
+    ['duplicate patterns', ['lib', 'lib'], ['lib']],
+    ['file extension', ['*.tgz'], ['*.tgz', '.tgz']],
+    ['potential empty string', ['/'], ['/']],
+    ['empty string', [''], []],
+  ])('handles %s', (_, pattern, expected) =>
+    expect(generateSimpleVariants(pattern)).toEqual(new Set(expected)),
+  );
+});
 
 describe('mergeWithIgnoreFile', () => {
   const baseTemplate =
-    '# managed by skuba\nnode_modules\n# end managed by skuba\n';
+    '# managed by skuba\nnode_modules*/\n# end managed by skuba\n';
   const updatedBaseTemplate =
-    '# managed by skuba\nnode_modules\n.DS_Store\n# end managed by skuba\n';
+    '# managed by skuba\nnode_modules*/\n.DS_Store\n# end managed by skuba\n';
 
   const cases = [
     ['empty provided', baseTemplate, ''],
 
     ['provided with no managed section', baseTemplate, '.DS_Store\n'],
+    [
+      'provided with managed section and partially superseded config',
+      updatedBaseTemplate,
+      'system32\n\n.DS_Store\nnode_modules/\n\n*.zip\n',
+    ],
+    [
+      'provided with managed section and fully superseded config',
+      updatedBaseTemplate,
+      '\r\n\nnode_modules\r\nnode_modules_bak',
+    ],
     [
       'provided with outdated managed section',
       updatedBaseTemplate,

src/cli/configure/processing/ignoreFile.ts

@@ -1,21 +1,69 @@
+/**
+ * Patterns that are superseded by skuba's bundled ignore file patterns and are
+ * non-trivial to derive using e.g. `generateSimpleVariants`.
+ */
+const OUTDATED_PATTERNS = ['node_modules_bak/', 'tmp-*/'];
+
+const ASTERISKS = /\*/g;
+const LEADING_SLASH = /^\//;
+const TRAILING_SLASH = /\/$/;
+
+/**
+ * Generate simple variants of an ignore pattern for exact matching purposes.
+ *
+ * Note that these patterns are not actually equivalent (e.g. `lib` matches more
+ * than `lib/`) but they generally represent the same _intent_.
+ */
+export const generateSimpleVariants = (patterns: string[]) => {
+  const set = new Set<string>();
+
+  for (const pattern of patterns) {
+    const deAsterisked = pattern.replace(ASTERISKS, '');
+
+    set.add(pattern);
+    set.add(deAsterisked);
+    set.add(deAsterisked.replace(LEADING_SLASH, ''));
+    set.add(deAsterisked.replace(TRAILING_SLASH, ''));
+    set.add(
+      deAsterisked.replace(LEADING_SLASH, '').replace(TRAILING_SLASH, ''),
+    );
+  }
+
+  set.delete('');
+
+  return set;
+};
+
 export const mergeWithIgnoreFile = (rawTemplateFile: string) => {
   const templateFile = rawTemplateFile.trim();
 
-  return (inputFile?: string) => {
-    if (typeof inputFile === 'undefined') {
+  const templatePatterns = generateSimpleVariants([
+    ...OUTDATED_PATTERNS,
+    ...templateFile.split('\n').map((line) => line.trim()),
+  ]);
+
+  return (rawInputFile?: string) => {
+    if (typeof rawInputFile === 'undefined') {
       return `${templateFile}\n`;
     }
 
-    const replacedFile = inputFile.replace(
-      /# managed by skuba[\s\S]*# end managed by skuba/,
-      templateFile,
-    );
+    const replacedFile = rawInputFile
+      .replace(/\r?\n/g, '\n')
+      .replace(/# managed by skuba[\s\S]*# end managed by skuba/, templateFile);
 
     if (replacedFile.includes(templateFile)) {
       return replacedFile;
     }
 
-    const outputFile = [templateFile, inputFile.trim()].join('\n\n').trim();
+    // Crunch the existing lines of a non-skuba config.
+    const migratedFile = replacedFile
+      .split('\n')
+      .filter((line) => !templatePatterns.has(line))
+      .join('\n')
+      .replace(/\n{3,}/g, '\n\n')
+      .trim();
+
+    const outputFile = [templateFile, migratedFile].join('\n\n').trim();
 
     return `${outputFile}\n`;
   };