pkg/analyzer_cli/lib/src/error_formatter.dart

// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

library analyzer_cli.src.error_formatter;

import 'package:analyzer/error/error.dart';
import 'package:analyzer/src/generated/engine.dart';
import 'package:analyzer/src/generated/source.dart';
import 'package:analyzer_cli/src/options.dart';
import 'package:path/path.dart' as path;

/// Returns the given error's severity.
ProcessedSeverity _identity(AnalysisError error) =>
    new ProcessedSeverity(error.errorCode.errorSeverity);

String _pluralize(String word, int count) => count == 1 ? word : word + "s";

/// Returns desired severity for the given [error] (or `null` if it's to be
/// suppressed).
typedef ProcessedSeverity _SeverityProcessor(AnalysisError error);

/// Analysis statistics counter.
class AnalysisStats {
  /// The total number of diagnostics sent to [formatErrors].
  int unfilteredCount;

  int errorCount;
  int hintCount;
  int lintCount;
  int warnCount;

  AnalysisStats() {
    init();
  }

  /// The total number of diagnostics reported to the user.
  int get filteredCount => errorCount + warnCount + hintCount + lintCount;

  /// (Re)set initial values.
  void init() {
    unfilteredCount = 0;
    errorCount = 0;
    hintCount = 0;
    lintCount = 0;
    warnCount = 0;
  }

  /// Print statistics to [out].
  void print(StringSink out) {
    var hasErrors = errorCount != 0;
    var hasWarns = warnCount != 0;
    var hasHints = hintCount != 0;
    var hasLints = lintCount != 0;
    bool hasContent = false;
    if (hasErrors) {
      out.write(errorCount);
      out.write(' ');
      out.write(_pluralize("error", errorCount));
      hasContent = true;
    }
    if (hasWarns) {
      if (hasContent) {
        if (!hasHints && !hasLints) {
          out.write(' and ');
        } else {
          out.write(", ");
        }
      }
      out.write(warnCount);
      out.write(' ');
      out.write(_pluralize("warning", warnCount));
      hasContent = true;
    }
    if (hasHints) {
      if (hasContent) {
        if (!hasLints) {
          out.write(' and ');
        } else {
          out.write(", ");
        }
      }
      out.write(hintCount);
      out.write(' ');
      out.write(_pluralize("hint", hintCount));
      hasContent = true;
    }
    if (hasLints) {
      if (hasContent) {
        out.write(" and ");
      }
      out.write(lintCount);
      out.write(' ');
      out.write(_pluralize("lint", lintCount));
      hasContent = true;
    }
    if (hasContent) {
      out.writeln(" found.");
    } else {
      out.writeln("No issues found!");
    }
  }
}

/// Helper for formatting [AnalysisError]s.
/// The two format options are a user consumable format and a machine consumable
/// format.
class ErrorFormatter {
  static final int _pipeCodeUnit = '|'.codeUnitAt(0);
  static final int _slashCodeUnit = '\\'.codeUnitAt(0);

  final StringSink out;
  final CommandLineOptions options;
  final AnalysisStats stats;

  final _SeverityProcessor processSeverity;

  ErrorFormatter(this.out, this.options, this.stats,
      [this.processSeverity = _identity]);

  /// Compute the severity for this [error] or `null` if this error should be
  /// filtered.
  ErrorSeverity computeSeverity(AnalysisError error) =>
      processSeverity(error)?.severity;

  void formatError(
      Map<AnalysisError, LineInfo> errorToLine, AnalysisError error) {
    Source source = error.source;
    LineInfo_Location location = errorToLine[error].getLocation(error.offset);
    int length = error.length;

    ProcessedSeverity processedSeverity = processSeverity(error);
    ErrorSeverity severity = processedSeverity.severity;

    if (options.machineFormat) {
      if (!processedSeverity.overridden) {
        if (severity == ErrorSeverity.WARNING && options.warningsAreFatal) {
          severity = ErrorSeverity.ERROR;
        }
      }
      out.write(severity);
      out.write('|');
      out.write(error.errorCode.type);
      out.write('|');
      out.write(error.errorCode.name);
      out.write('|');
      out.write(escapePipe(source.fullName));
      out.write('|');
      out.write(location.lineNumber);
      out.write('|');
      out.write(location.columnNumber);
      out.write('|');
      out.write(length);
      out.write('|');
      out.write(escapePipe(error.message));
      out.writeln();
    } else {
      // Get display name.
      String errorType = severity.displayName;

      // Translate INFOs into LINTS and HINTS.
      if (severity == ErrorSeverity.INFO) {
        if (error.errorCode.type == ErrorType.HINT ||
            error.errorCode.type == ErrorType.LINT) {
          errorType = error.errorCode.type.displayName;
        }
      }

      int indent = errorType.length + 3;

      // [warning] 'foo' is not a bar at lib/foo.dart:1:2 (foo_warning).
      String message = error.message;
      // Remove any terminating '.' from the end of the message.
      if (message.endsWith('.')) {
        message = message.substring(0, message.length - 1);
      }
      out.write('[$errorType] $message ');
      String sourceName;
      if (source.uriKind == UriKind.DART_URI) {
        sourceName = source.uri.toString();
      } else if (source.uriKind == UriKind.PACKAGE_URI) {
        sourceName = _relative(source.fullName);
        if (sourceName == source.fullName) {
          // If we weren't able to shorten the path name, use the package: version.
          sourceName = source.uri.toString();
        }
      } else {
        sourceName = _relative(source.fullName);
      }
      out.write('at $sourceName');
      out.write(':${location.lineNumber}:${location.columnNumber} ');
      out.write('(${error.errorCode.name.toLowerCase()}).');
      out.writeln();

      // If verbose, also print any associated correction.
      if (options.verbose && error.correction != null) {
        out.writeln('${' '.padLeft(indent)}${error.correction}');
      }
    }
  }

  void formatErrors(List<AnalysisErrorInfo> errorInfos) {
    stats.unfilteredCount += errorInfos.length;

    var errors = new List<AnalysisError>();
    var errorToLine = new Map<AnalysisError, LineInfo>();
    for (AnalysisErrorInfo errorInfo in errorInfos) {
      for (AnalysisError error in errorInfo.errors) {
        if (computeSeverity(error) != null) {
          errors.add(error);
          errorToLine[error] = errorInfo.lineInfo;
        }
      }
    }
    // Sort errors.
    errors.sort((AnalysisError error1, AnalysisError error2) {
      // Severity.
      ErrorSeverity severity1 = computeSeverity(error1);
      ErrorSeverity severity2 = computeSeverity(error2);
      int compare = severity2.compareTo(severity1);
      if (compare != 0) {
        return compare;
      }
      // Path.
      compare = Comparable.compare(error1.source.fullName.toLowerCase(),
          error2.source.fullName.toLowerCase());
      if (compare != 0) {
        return compare;
      }
      // Offset.
      return error1.offset - error2.offset;
    });
    // Format errors.
    for (AnalysisError error in errors) {
      ProcessedSeverity processedSeverity = processSeverity(error);
      ErrorSeverity severity = processedSeverity.severity;
      if (severity == ErrorSeverity.ERROR) {
        stats.errorCount++;
      } else if (severity == ErrorSeverity.WARNING) {
        // Only treat a warning as an error if it's not been set by a processor.
        if (!processedSeverity.overridden && options.warningsAreFatal) {
          stats.errorCount++;
        } else {
          stats.warnCount++;
        }
      } else if (error.errorCode.type == ErrorType.HINT) {
        stats.hintCount++;
      } else if (error.errorCode.type == ErrorType.LINT) {
        stats.lintCount++;
      }
      formatError(errorToLine, error);
    }
  }

  static String escapePipe(String input) {
    StringBuffer result = new StringBuffer();
    for (int c in input.codeUnits) {
      if (c == _slashCodeUnit || c == _pipeCodeUnit) {
        result.write('\\');
      }
      result.writeCharCode(c);
    }
    return result.toString();
  }
}

/// A severity with awareness of whether it was overridden by a processor.
class ProcessedSeverity {
  ErrorSeverity severity;
  bool overridden;
  ProcessedSeverity(this.severity, [this.overridden = false]);
}

/// Given an absolute path, return a relative path if the file is contained in
/// the current directory; return the original path otherwise.
String _relative(String file) {
  return file.startsWith(path.current) ? path.relative(file) : file;
}