Coverage Diff

quality.coverage_diff

ProductionBounded custom (Class B)Deterministicstrictfastv1.0.0

No network

Overview

You send two coverage snapshots as arrays of closed path counters: lines, branches and functions, each as covered and total integers. pathMode defaults to EXACT; SLASH_NORMALIZED rewrites backslashes to slashes, collapses repeated slashes and strips a trailing slash. The answer is global and per-path deltas, added and removed paths, and line-coverage regressions sorted by magnitude. A percentage is JSON null when its total is zero, never NaN. This does not parse vendor reports or set a pass bar.

Two coverage snapshots need a published integer delta, not a vendor-file parser.

Reliability

Percentages round to six decimals. A percentage is JSON null when its total is zero. COVERAGE_DIFF_INVALID — trigger: a covered count exceeds its total, a blank path, or an unknown pathMode; retryable: no; next: send non-negative counters with covered ≤ total. COVERAGE_DIFF_PATH_COLLISION — trigger: two paths become the same string after pathMode; retryable: no; next: send unique paths under that mode. COVERAGE_DIFF_LIMIT_EXCEEDED — trigger: more than 100000 paths on one side; retryable: no; next: split the snapshots.

Context footprint

Paths and integer counters only; source text is never returned. A successful call costs 1 execution credit.

When to use it

When two already-normalized coverage tables must be compared by path.

When the report is still a JaCoCo or LCOV file, or when a pass bar is required.

Scope

Note

Compares two coverage snapshots by path and reports count and percentage-point deltas.

Non-goals

Does not parse vendor coverage reports
Does not set a pass or fail bar
Does not merge overlapping shards

Properties

IdempotentRetry safeStreaming supportedFile input supportedRequires external service

Capabilities

analysis

Cost & billing

Flat rate per invocation

MetercallsBillable onsuccessCost per call1 credit

File handling

Accepts file_refProduces file_refMax input2 MB

How we handle your data

Sensitive processing

What this means

This skill is designed to detect, mask, redact, validate, or otherwise process sensitive data.

Squillify guarantees

Runs inside Squillify
This skill runs inside Squillify.
Payloads are not sent to an external service by this skill.
Squillify does not permanently store submitted payloads.
Telemetry records metadata only, not submitted content.
Submitted payloads are not used for training.
Submitted payloads are not reviewed by humans.
Targets sensitive data
The response does not contain submitted content.

Your responsibility

Squillify does not determine whether submitted content is sensitive. Your application is responsible for deciding what data it is allowed to submit. Your application is responsible for securing the response.

Read the Microskill Data Handling Policy

Input schema

Field	Type	Required	Description
before	array	Yes	Before snapshot, 0 through 100001 closed path objects; runtime accepts at most 100000.
after	array	Yes	After snapshot, 0 through 100001 closed path objects; runtime accepts at most 100000.
pathMode	string	No	EXACT or SLASH_NORMALIZED; omit it for EXACT matching of the path strings as sent.

Output schema

Field	Type	Required	Description
pathMode	string	Yes	Path matching mode that was actually applied to both snapshots.
global	object	Yes	Closed aggregate line, branch and function deltas across every path in either snapshot.
paths	array	Yes	Per-path deltas sorted by path, 0 through 200000 closed rows.
added	array	Yes	Normalized paths present only after, sorted lexicographically, 0 through 100000 strings of 1 through 4096 characters.
removed	array	Yes	Normalized paths present only before, sorted lexicographically, 0 through 100000 strings of 1 through 4096 characters.
regressions	array	Yes	Line-coverage drops sorted by magnitude then path, 0 through 100000 closed {path, metric, beforePercentage, afterPercentage, magnitudePp} objects.
beforeCount	integer	Yes	How many distinct before paths were compared.
afterCount	integer	Yes	How many distinct after paths were compared.

API contract

POST /v1/execute

curl

curl -sS -X POST "$BASE/v1/execute" -H "Authorization: Bearer $KEY" -H 'Content-Type: application/json' -d '{"skillKey":"quality.coverage_diff","input":{"before":[{"path":"src/App.java","linesCovered":8,"linesTotal":10,"branchesCovered":2,"branchesTotal":4,"functionsCovered":1,"functionsTotal":1}],"after":[{"path":"src/App.java","linesCovered":5,"linesTotal":10,"branchesCovered":2,"branchesTotal":4,"functionsCovered":1,"functionsTotal":1}]}}'

Integrations

TypeScript SDK

import { Squillify } from "@squillify/sdk";

const sq = new Squillify({ apiKey: process.env.SQUILLIFY_API_KEY });

const { output } = await sq.execute("quality.coverage_diff", {"before":[{"path":"src/App.java","linesCovered":8,"linesTotal":10,"branchesCovered":2,"branchesTotal":4,"functionsCovered":1,"functionsTotal":1}],"after":[{"path":"src/App.java","linesCovered":5,"linesTotal":10,"branchesCovered":2,"branchesTotal":4,"functionsCovered":1,"functionsTotal":1}]});

Errors

Code	HTTP	Retryable	Description
VALIDATION_ERROR	400	No	The request payload failed schema validation.
UNAUTHORIZED	401	No	Missing or invalid API key.
SKILL_NOT_ACCESSIBLE	403	No	The API key is not granted access to this skill.
SKILL_NOT_AVAILABLE_FOR_PLAN	403	No	This skill is not included in your current plan.
PLAN_ELIGIBILITY_UNAVAILABLE	503	Yes	Plan eligibility could not be decided. Retry after backoff.
SKILL_NOT_FOUND	404	No	The requested skill or version does not exist.
TENANT_RATE_LIMITED	429	Yes	Request rate limit exceeded. Retry after backoff.
QUOTA_EXCEEDED	429	Yes	Plan quota exhausted. Retryable once the quota period resets.
EXECUTION_TIMEOUT	504	Yes	Execution exceeded the allowed time budget.
COVERAGE_DIFF_INVALID	400	No	The request payload failed this skill's input validation.
COVERAGE_DIFF_PATH_COLLISION	400	No	The request payload failed this skill's input validation.
COVERAGE_DIFF_LIMIT_EXCEEDED	429	No	A size, quota, rate, or time limit was exceeded.

Other limits

Limit	Value
Recommended inline bytes	32 KiB

Limitations

Does not parse vendor coverage reports
Does not set a pass or fail bar
Does not merge overlapping shards
Parsing a JaCoCo XML file
Deciding whether coverage is high enough

How to call

POST /v1/execute (requires authentication)

Request bodyjson

{
  "skillKey": "quality.coverage_diff",
  "input": {
    "before": [
      {
        "path": "src/App.java",
        "linesCovered": 8,
        "linesTotal": 10,
        "branchesCovered": 2,
        "branchesTotal": 4,
        "functionsCovered": 1,
        "functionsTotal": 1
      }
    ],
    "after": [
      {
        "path": "src/App.java",
        "linesCovered": 5,
        "linesTotal": 10,
        "branchesCovered": 2,
        "branchesTotal": 4,
        "functionsCovered": 1,
        "functionsTotal": 1
      }
    ]
  }
}

Examples

A ten-line file that loses three covered lines is a regression

Inputjson

{
  "before": [
    {
      "path": "src/App.java",
      "linesCovered": 8,
      "linesTotal": 10,
      "branchesCovered": 2,
      "branchesTotal": 4,
      "functionsCovered": 1,
      "functionsTotal": 1
    }
  ],
  "after": [
    {
      "path": "src/App.java",
      "linesCovered": 5,
      "linesTotal": 10,
      "branchesCovered": 2,
      "branchesTotal": 4,
      "functionsCovered": 1,
      "functionsTotal": 1
    }
  ]
}

Expected outputjson

{
  "pathMode": "EXACT",
  "paths": [
    {
      "path": "src/App.java",
      "change": "CHANGED",
      "lines": {
        "beforeCovered": 8,
        "beforeTotal": 10,
        "afterCovered": 5,
        "afterTotal": 10,
        "deltaCovered": -3,
        "deltaTotal": 0,
        "beforePercentage": 80,
        "afterPercentage": 50,
        "deltaPp": -30
      },
      "branches": {
        "beforeCovered": 2,
        "beforeTotal": 4,
        "afterCovered": 2,
        "afterTotal": 4,
        "deltaCovered": 0,
        "deltaTotal": 0,
        "beforePercentage": 50,
        "afterPercentage": 50,
        "deltaPp": 0
      },
      "functions": {
        "beforeCovered": 1,
        "beforeTotal": 1,
        "afterCovered": 1,
        "afterTotal": 1,
        "deltaCovered": 0,
        "deltaTotal": 0,
        "beforePercentage": 100,
        "afterPercentage": 100,
        "deltaPp": 0
      }
    }
  ],
  "added": [],
  "removed": [],
  "regressions": [
    {
      "path": "src/App.java",
      "metric": "lines",
      "beforePercentage": 80,
      "afterPercentage": 50,
      "magnitudePp": 30
    }
  ],
  "global": {
    "lines": {
      "beforeCovered": 8,
      "beforeTotal": 10,
      "afterCovered": 5,
      "afterTotal": 10,
      "deltaCovered": -3,
      "deltaTotal": 0,
      "beforePercentage": 80,
      "afterPercentage": 50,
      "deltaPp": -30
    },
    "branches": {
      "beforeCovered": 2,
      "beforeTotal": 4,
      "afterCovered": 2,
      "afterTotal": 4,
      "deltaCovered": 0,
      "deltaTotal": 0,
      "beforePercentage": 50,
      "afterPercentage": 50,
      "deltaPp": 0
    },
    "functions": {
      "beforeCovered": 1,
      "beforeTotal": 1,
      "afterCovered": 1,
      "afterTotal": 1,
      "deltaCovered": 0,
      "deltaTotal": 0,
      "beforePercentage": 100,
      "afterPercentage": 100,
      "deltaPp": 0
    }
  },
  "beforeCount": 1,
  "afterCount": 1
}

Tip

Line coverage falls from 80 to 50, so the path is listed as a regression.

A unit with total zero reports JSON null percentages, never NaN