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Calculate Metrics

Reports code metrics for Dart code.

To execute the command, run:

$ dcm calculate-metrics lib # or dcm cm lib
info

You need to configure metrics entry in the analysis_options.yaml to have a metrics report included into the result.

Full command description:

Usage: dcm calculate-metrics [arguments] <directories>
-h, --help                                         Print this usage information.


-r, --reporter=<console>                           Analysis output format.
                                                   [console (default), html, json, codeclimate, gitlab, checkstyle]
-o, --output-directory=<OUTPUT>                    Write HTML output to OUTPUT.
                                                   (defaults to "metrics")
    --open                                         Automatically open generated HTML report.
    --json-path=<path/to/file.json>                Path to the JSON file with the analysis output.
    --report-all                                   Report all metric results (default is to report only high or very high metric levels, works only for the console reporter).


-c, --print-config                                 Print resolved config.


    --root-folder=<./>                             Root folder.
                                                   (defaults to the current directory)
    --sdk-path=<directory-path>                    Dart SDK directory path.
                                                   If the project has a `.fvm/flutter_sdk` symlink, it will be used if the SDK is not found.
    --exclude=<{**/*.g.dart,**/*.freezed.dart}>    File paths in Glob syntax to be exclude.
                                                   (defaults to "{**/*.g.dart,**/*.freezed.dart}")


    --no-congratulate                              Don't show output even when there are no issues.


    --verbose                                      Show verbose logs.


    --ci-key                                       The license key to run on CI server. Can be provided via DCM_CI_KEY env variable.
    --email                                        The email used to purchase the license. Can be provided via DCM_EMAIL env variable.


    --no-analytics                                 Disable sending anonymous usage statistics.


    --fatal-level=<high>                           Treat given or higher metric level as fatal.
                                                   [near, high, very high]

Output example​

Console​

Use --reporter=console to enable this format.

Console

HTML​

Use --reporter=html to enable this format.

HTML report overview​

HTML

HTML single file report​

HTML

JSON​

The reporter prints a single JSON object containing meta information and the violations grouped by a file. Use --reporter=json to enable this format.

The root object fields are​

  • formatVersion - an integer representing the format version (will be incremented each time the serialization format changes)
  • timestamp - a creation time of the report in YYYY-MM-DD HH:MM:SS format
  • records - an array of objects
  • summary - an array of objects
{
  "formatVersion": 2,
  "timestamp": "2021-04-11 14:44:42",
  "records": [
    {
      ...
    },
    {
      ...
    },
    {
      ...
    }
  ],
  "summary": [
    {
      ...
    },
    {
      ...
    }
  ]
}

The record object fields are​

  • path - a relative path to the target file
  • fileMetrics - an array with target file metrics
  • classes - a map with class name as the key and class report as the value
  • functions - a map with function name as the key and function report as the value
{
  "path": "lib/src/metrics/metric_computation_result.dart",
  "classes": {
    ...
  },
  "functions": {
    ...
  },
  "fileMetrics": {
    ...
  }
}

The summary-record object fields are​

  • title - a message with information about the record
  • value - an actual value of this record (can be an array or a single value)
  • violations - a value of a violations count of a metric associated with this record
{
    "title": "Average Cyclomatic Number per line of code",
    "value": 0.3447098976109215,
    "violations": 5
}

The report object fields are​

  • codeSpan - a source code span of the target entity
  • metrics - an array with target entity metrics
{
  "codeSpan": {
    ...
  },
  "metrics": [
    ...
  ]
}

The code span object fields are​

  • start - a start location of an entity
  • end - an end location of an entity
  • text - a source code text of an entity
{
  "start": {
    ...
  },
  "end": {
    ...
  },
  "text": "entity source code"
}

The location object fields are​

  • offset - a zero-based offset of the location in the source
  • line - a zero-based line of the location in the source
  • column - a zero-based column of the location in the source
{
  "offset": 156,
  "line": 7,
  "column": 1
}

The metric value object fields are​

  • metricsId - an id of the computed metric
  • value - an actual value computed by the metric
  • unitType - a human readable unit type (optional)
  • level - a level of the value computed by the metric
  • comment - a message with information about the value
  • recommendation - a message with information about how the user can improve the value (optional)
  • context - an additional information associated with the value that helps understand how the metric was computed
{
  "metricsId": "number-of-methods",
  "value": 14,
  "unitType": "methods",
  "level": "warning",
  "comment": "This class has 14 methods, which exceeds the maximum of 10 allowed.",
  "recommendation": "Consider breaking this class up into smaller parts.",
  "context": [
    ...
  ]
}

The context message object fields are​

  • message - an message to be displayed to the user
  • codeSpan - a source code span associated with or referenced by the message
{
  "message": "getter complexityEntities increase metric value",
  "codeSpan": {
    ...
  }
}

GitLab and Code Climate​

GitLab and Code Climate formats are also supported. Refer to the analyze commands docs to set up them.

Checkstyle​

Use --reporter=checkstyle to enable this format.

<?xml version="1.0"?>
<checkstyle version="10.0">
  <file name="../abstract_class.dart">
    <error line="0" message="metric comment" severity="warning" source="file-metric-id"/>
    <error line="0" severity="error" message="metric comment" source="id"/>
  </file>
  <file name="../class_with_factory_constructors.dart">
    <error line="0" severity="warning" message="metric comment" source="id"/>
  </file>
</checkstyle>