From 30fe8aefa88dedced6bc5f746b36b2a5509b0c43 Mon Sep 17 00:00:00 2001
From: Joe Hildebrand <joe-github@cursive.net>
Date: Sun, 2 Jul 2023 13:14:22 -0600
Subject: [PATCH] Optionally process 'unset' properties.  Fixes #123

---
 CHANGELOG.md      | 13 +++++++++++++
 src/cli.ts        |  2 ++
 src/index.test.ts | 17 +++++++++++++++++
 src/index.ts      | 24 ++++++++++++++++++++++++
 4 files changed, 56 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7292bf0..b24fdc1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,16 @@
+## 2.0.0
+
+- **Breaking**: Now requires Node v16+
+- Enable extended globbing from minimatch.  This means that some patterns will
+  work in this version might not work in other editorconfig implementations.
+  Fixes #84.
+- Add `unset` option to API and CLI.  When enabled, properties with the value
+  "unset" will be removed from the returned object.  Defaults to false in all
+  cases, since according to the core team, this is something that the editor
+  plugin is supposed to do, and the tests reinforce this. An `unset()`
+  function is now exported if you'd like to call it explicitly.
+  Fixes #123.
+
 ## 1.0.3
 
 - Updated all dependencies, including security fixes for semver 7.3.8
diff --git a/src/cli.ts b/src/cli.ts
index 0475b94..f630fa2 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -54,6 +54,7 @@ export default async function cli(
     .option('-f <path>',       'Specify conf filename other than \'.editorconfig\'')
     .option('-b <version>',    'Specify version (used by devs to test compatibility)')
     .option('--files',         'Output file names that contributed to the configuration, rather than the configuation itself')
+    .option('--unset',         'Remove all properties whose final value is \'unset\'')
     .parse(args)
 
   const files = program.args
@@ -73,6 +74,7 @@ export default async function cli(
         version: opts.b as string,
         files: visited ? visited[i++] : undefined,
         cache,
+        unset: Boolean(opts.unset),
       }))
     }
     return p
diff --git a/src/index.test.ts b/src/index.test.ts
index 9de2124..5b0ea50 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -200,3 +200,20 @@ indent_size = 3`))
     matcher(path.join(__dirname, 'foo.json')).should.match({ indent_size: 3 })
   })
 })
+
+describe('unset', () => {
+  it('pair witht the value `unset`', () => {
+    const matcher = editorconfig.matcher({
+      root: __dirname,
+      unset: true,
+    }, Buffer.from(`\
+[*]
+indent_size = 4
+
+[*.json]
+indent_size = unset
+`))
+    matcher(path.join(__dirname, 'index.js')).should.match({ indent_size: 4 })
+    matcher(path.join(__dirname, 'index.json')).should.be.eql({ })
+  })
+})
diff --git a/src/index.ts b/src/index.ts
index fc260fd..346aff1 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -61,6 +61,7 @@ export interface ParseOptions {
   root?: string
   files?: Visited[]
   cache?: Cache
+  unset?: boolean
 }
 
 const knownPropNames: (keyof KnownProps)[] = [
@@ -426,6 +427,7 @@ function opts(filepath: string, options: ParseOptions = {}): [
       root: path.resolve(options.root || path.parse(resolvedFilePath).root),
       files: options.files,
       cache: options.cache,
+      unset: options.unset,
     },
   ]
 }
@@ -507,11 +509,33 @@ function combine(
         }
       }
     }
+
     return props
   }, {})
+
+  if (options.unset) {
+    unset(ret)
+  }
+
   return processMatches(ret, options.version as string)
 }
 
+/**
+ * For any pair, a value of `unset` removes the effect of that pair, even if
+ * it has been set before.  This method modifies the properties object in
+ * place to remove any property that has a value of `unset`.
+ *
+ * @param props Properties object to modify.
+ */
+export function unset(props: Props): void {
+  const keys = Object.keys(props)
+  for (const k of keys) {
+    if (props[k] === 'unset') {
+      delete props[k]
+    }
+  }
+}
+
 /**
  * Find all of the properties from matching sections in config files in the
  * same directory or toward the root of the filesystem.