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Sentiment analyzer reference

The sentiment analyzer classifies comment sentiment across Git history, extracting new or changed comments via UAST parsing and classifying them as positive, negative, or neutral.

For the conceptual model — how comments are filtered and scored, the multilingual lexicon, and the software-engineering domain adjustments — see Understanding comment sentiment analysis. To run it, see the Quick start.

Configuration options

Option Type Default Description
CommentSentiment.MinLength int 20 Minimum character length for a comment to be analyzed. Comments shorter than this are skipped.
CommentSentiment.Gap float 0.5 Sentiment score threshold. Values must be in the range (0, 1). Higher values require stronger sentiment signal to classify as positive/negative. 
# .codefang.yml
history:
  sentiment:
    min_comment_length: 20
    gap: 0.5

Tuning the gap

A gap of 0.5 is conservative -- only strongly positive or negative comments are flagged. Lower it to 0.3 for more sensitivity, or raise to 0.7 to capture only the most extreme sentiments.

The analyzer requires UAST support to extract comments and is automatically enabled when the UAST pipeline is available.

Output formats

JSON output

{
  "time_series": [
    {
      "tick": 0,
      "start_time": "2024-01-15T10:30:00Z",
      "end_time": "2024-01-16T08:45:00Z",
      "sentiment": 0.72,
      "comment_count": 12,
      "commit_count": 5,
      "classification": "positive"
    },
    {
      "tick": 1,
      "start_time": "2024-01-16T09:00:00Z",
      "end_time": "2024-01-17T18:30:00Z",
      "sentiment": 0.35,
      "comment_count": 8,
      "commit_count": 3,
      "classification": "negative"
    }
  ],
  "trend": {
    "start_tick": 0,
    "end_tick": 10,
    "start_sentiment": 0.68,
    "end_sentiment": 0.52,
    "trend_direction": "declining",
    "change_percent": -23.5
  },
  "low_sentiment_periods": [
    {
      "tick": 5,
      "sentiment": 0.18,
      "comments": ["This is a terrible hack"],
      "risk_level": "HIGH"
    }
  ],
  "aggregate": {
    "total_ticks": 10,
    "total_comments": 245,
    "total_commits": 89,
    "average_sentiment": 0.56,
    "positive_ticks": 4,
    "neutral_ticks": 3,
    "negative_ticks": 3
  }
}

Plot output

The HTML plot includes:

  1. Sentiment Over Time: Line chart with sentiment score, positive/negative threshold bands (dashed lines), regression trend line, and comment count on a secondary axis
  2. Sentiment Distribution: Donut chart showing the breakdown of positive, neutral, and negative time periods

The plot uses semantic colors (green = positive, yellow = neutral, red = negative) and includes interpretive hints.

Terminal output

The terminal renderer provides a colored, Unicode-rich summary:

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ SENTIMENT ANALYSIS                                       💬 ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛

  Summary
────────────────────────────────────────────────────────────────
  Average Sentiment: [██████████░░░░░░░░░░] 5/10 😐
  Total Ticks:       10
  Total Comments:    245
  Total Commits:     89

  Distribution
────────────────────────────────────────────────────────────────
  😊 Positive (≥0.6)  ████████░░░░░░░░░░░░  40%  (4)
  😐 Neutral           ██████░░░░░░░░░░░░░░  30%  (3)
  😟 Negative (≤0.4)  ██████░░░░░░░░░░░░░░  30%  (3)

  Trend
────────────────────────────────────────────────────────────────
  Direction: ↘ declining
  Start (tick 0): 0.68  →  End (tick 10): 0.52
  Change: -23.5%

  Sentiment Timeline
────────────────────────────────────────────────────────────────
  ▇▆▅▄▃▂▃▄▅▆
  neg              pos

See also