added doiuse plugin for postcss

1 files changed, 80 insertions, 0 deletions

diff --git a/node_modules/doiuse/lib/stream/RuleUsageTransform.js b/node_modules/doiuse/lib/stream/RuleUsageTransform.js
new file mode 100644
index 00000000..a2a79d4d
--- /dev/null
+++ b/node_modules/doiuse/lib/stream/RuleUsageTransform.js
@@ -0,0 +1,80 @@
+/* eslint-disable no-underscore-dangle */
+import { Transform } from 'node:stream';
+
+import postcss from 'postcss';
+import sourcemap from 'source-map';
+
+import DoIUse from '../DoIUse.js';
+
+/** @typedef {import('../../data/features.js').FeatureKeys} FeatureKeys */
+/** @typedef {import('./SourceMapTransform.js').SourceMapTransformation} SourceMapTransformation */
+
+export default class RuleUsageTransform extends Transform {
+  /** @type {import("postcss").Processor} */
+  #processor;
+
+  #skipErrors;
+
+  #filename;
+
+  /**
+   * @param {Object} options
+   * @param {string} options.browsers
+   * @param {FeatureKeys[]} [options.ignore]
+   * @param {boolean} [options.skipErrors]
+   * @param {string} [filename]  Filename for outputting source code locations.
+   */
+  constructor(options, filename = '<streaming css input>') {
+    super({
+      objectMode: true,
+    });
+    this.#processor = postcss([new DoIUse({
+      browsers: options.browsers,
+      ignore: options.ignore,
+      onFeatureUsage: (usage) => {
+        this.push(usage);
+      },
+    })]);
+    this.#filename = filename;
+    this.#skipErrors = options.skipErrors;
+  }
+
+  /**
+   * @param {SourceMapTransformation} rule
+   * @param {any} encoding
+   * @param {Function} callback
+   */
+  async _transform(rule, encoding, callback) {
+    let caughtError;
+    try {
+      const mapper = new sourcemap.SourceMapGenerator();
+      const lines = rule.content.split('\n');
+      let oline = rule.line;
+      let ocol = rule.column;
+      for (const [lineNumber, content] of lines.entries()) {
+        mapper.addMapping({
+          generated: { line: lineNumber + 1, column: 1 },
+          original: { line: oline, column: ocol },
+          source: this.#filename,
+        });
+        mapper.addMapping({
+          generated: { line: lineNumber + 1, column: content.length },
+          original: { line: oline, column: ocol + content.length },
+          source: this.#filename,
+        });
+        oline += 1;
+        ocol = 1;
+      }
+      await this.#processor.process(rule.content, {
+        from: this.#filename, map: { prev: mapper.toString() },
+      });
+    } catch (error) {
+      if (this.#skipErrors) {
+        this.emit('warning', error);
+      } else {
+        caughtError = error;
+      }
+    }
+    callback(caughtError);
+  }
+}