src/workflow/problem_matcher.ts

// Copyright 2025 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import path from 'path';
import * as vscode from 'vscode';

const buildSeverity: Record<string, vscode.DiagnosticSeverity> = {
  'error': vscode.DiagnosticSeverity.Error,
  'warn': vscode.DiagnosticSeverity.Warning,
  'note': vscode.DiagnosticSeverity.Information
};

/**
 * Diagnostic Collection Class
 * Checks for C++ and Rust build syntax errors from Fuchsia builds and routes
 * to the extension's problem matcher.
 *
 * Python and GN are not included since the recommended language server extensions
 * handle these cases.
 */
export class FuchsiaDiagnostics {
  private collection = vscode.languages.createDiagnosticCollection('fuchsia');
  private entries: Array<[vscode.Uri, vscode.Diagnostic[]]> = [];
  private fileSet: Set<string> = new Set();
  private fuchsiaProblemMatcher: any;

  constructor(packageJSON: any) {
    this.fuchsiaProblemMatcher = packageJSON.contributes.problemMatchers;
  }

  /**
   * Matches message and adds to diagnostics collection
   * @param msg Message to match to problem matcher
   */
  match(msg: string) {
    const matcher = this.fuchsiaProblemMatcher.find(
      (item: { name: string; }) => item.name === 'cpp-rust-build');
    const pattern = new RegExp(matcher!.pattern.regexp, 'g');
    const matches = msg.matchAll(pattern);

    // Assumes in fuchsia directory
    const workspaceFolder = vscode.workspace.workspaceFolders;
    if (!workspaceFolder) {
      return;
    }
    const workspacePath = workspaceFolder[0].uri.fsPath;

    // Prevent duplicates of matches
    for (const match of matches) {
      if (this.fileSet.has(match[0])) {
        continue;
      }
      this.fileSet.add(match[0]);
      const fullPath = path.join(workspacePath, match[matcher!.pattern.file]);
      this.entries.push([vscode.Uri.file(fullPath), [{
        message: match[matcher!.pattern.message],
        range: new vscode.Range(
          new vscode.Position(parseInt(match[matcher!.pattern.line]) - 1,
            parseInt(match[matcher!.pattern.column]) - 1),
          new vscode.Position(parseInt(match[matcher!.pattern.line]) - 1,
            parseInt(match[matcher!.pattern.column]) - 1)),
        severity: buildSeverity[match[matcher!.pattern.severity]]
      }]]);
    }
    this.collection.set(this.entries);
  }

  /**
   * Clear the collection
   */
  clear() {
    this.entries = [];
    this.fileSet.clear();
    this.collection.clear();
  }

  /**
   * Returns current list of matches for a uri resource
   * @returns
   */
  get(): Array<[vscode.Uri, vscode.Diagnostic[]]> {
    let collection: Array<[vscode.Uri, vscode.Diagnostic[]]> = [];
    this.entries.forEach((entry) => {
      console.log(entry[0]);
      let uri = entry[0];
      let getDiagnostics = this.collection.get(uri);
      if (getDiagnostics) {
        collection.push([uri, [...getDiagnostics]]);
      }
    });
    return collection;
  }
}