add threshold-uncovered option

allows threshold to be set by number of uncovered lines instead of percentage
of coverage.

In a codebase which continuously grows, if you fix the number of lines uncovered
then you (loosely) enforce that all new code should be covered.

closes rpl#168

package.json

@@ -15,6 +15,7 @@
   "scripts": {
     "ava": "nyc ava --verbose",
     "build": "rimraf dist && babel -d dist src --only src/lib --source-maps",
+    "dev": "babel -d dist src --only src/lib --source-maps --watch",
     "update-flow-typed": "rimraf flow-typed && flow-typed install -s -i dev",
     "flow-coverage": "bin/flow-coverage-report.js",
     "flow-check": "flow check",
@@ -185,7 +186,7 @@
       "\\.jsx$": "babel-jest"
     },
     "transformIgnorePatterns": [
-      "node_modules/(?!(svgo)/)"
+      "node_modules/(?!(svgo|badge-up)/)"
     ],
     "testEnvironment": "node",
     "testMatch": [

src/__tests__/fixtures.js

@@ -33,6 +33,7 @@ const FLOW_COVERAGE_SUMMARY_DATA = {
   covered_count: 5,
   uncovered_count: 5,
   threshold: 40,
+  uncoveredThreshold: 3,
   percent: 50,
   globIncludePatterns: [firstGlob, secondGlob],
   files: allFiles.reduce((acc, filename) => {

src/__tests__/react-components/__snapshots__/test-coverage-meter-bar.js.snap

@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`<FlowCoverageMeterBar /> 1`] = `
+exports[`<FlowCoverageMeterBar /> percent <= threshold 1`] = `
 <div
   className="row red"
   style={
@@ -11,3 +11,15 @@ exports[`<FlowCoverageMeterBar /> 1`] = `
   }
 />
 `;
+
+exports[`<FlowCoverageMeterBar /> uncoveredCount <= thresholdUncovered 1`] = `
+<div
+  className="row green"
+  style={
+    Object {
+      "height": 12,
+      "padding": 0,
+    }
+  }
+/>
+`;

src/__tests__/react-components/__snapshots__/test-coverage-summary-table.js.snap

@@ -83,3 +83,45 @@ exports[`<FlowCoverageSummaryTable /> 2`] = `
   </tbody>
 </table>
 `;
+
+exports[`<FlowCoverageSummaryTable /> 3`] = `
+<table
+  className="ui small celled table"
+>
+  <thead>
+    <tr>
+      <th>
+        Percent
+      </th>
+      <th>
+        Total
+      </th>
+      <th>
+        Covered
+      </th>
+      <th>
+        Uncovered
+      </th>
+    </tr>
+  </thead>
+  <tbody>
+    <tr
+      className="positive"
+    >
+      <td>
+        50
+         %
+      </td>
+      <td>
+        10
+      </td>
+      <td>
+        5
+      </td>
+      <td>
+        5
+      </td>
+    </tr>
+  </tbody>
+</table>
+`;

src/__tests__/react-components/test-coverage-meter-bar.js

@@ -9,14 +9,26 @@ import {BASE_DIR} from './common';
 
 const REACT_COMPONENT = `${BASE_DIR}/coverage-meter-bar`;
 
-test('<FlowCoverageMeterBar />', () => {
-  const FlowCoverageMeterBar = require(REACT_COMPONENT).default;
-  const props = {
-    percent: 20,
-    threshold: 80
-  };
-  const tree = renderer.create(<FlowCoverageMeterBar {...props}/>).toJSON();
-  expect(tree).toMatchSnapshot();
+describe('<FlowCoverageMeterBar />', () => {
+  test('percent <= threshold', () => {
+    const FlowCoverageMeterBar = require(REACT_COMPONENT).default;
+    const props = {
+      percent: 20,
+      threshold: 80
+    };
+    const tree = renderer.create(<FlowCoverageMeterBar {...props}/>).toJSON();
+    expect(tree).toMatchSnapshot();
+  });
+
+  test('uncoveredCount <= thresholdUncovered', () => {
+    const FlowCoverageMeterBar = require(REACT_COMPONENT).default;
+    const props = {
+      uncoveredCount: 20,
+      thresholdUncovered: 30
+    };
+    const tree = renderer.create(<FlowCoverageMeterBar {...props}/>).toJSON();
+    expect(tree).toMatchSnapshot();
+  });
 });
 
 test.skip('<FlowCoverageMeterBar /> with missing props');

src/__tests__/react-components/test-coverage-summary-table.js

@@ -21,12 +21,19 @@ test('<FlowCoverageSummaryTable />', () => {
   const positiveSummaryTree = renderer.create(<FlowCoverageSummaryTable {...positiveSummaryProps}/>).toJSON();
   expect(positiveSummaryTree).toMatchSnapshot();
 
-  // Expect positive with higher threshold.
+  // Expect negative with higher threshold.
   const negativeSummaryProps = {
     coverageSummaryData: {...FLOW_COVERAGE_SUMMARY_DATA, threshold: 90}
   };
   const negativeSummaryTree = renderer.create(<FlowCoverageSummaryTable {...negativeSummaryProps}/>).toJSON();
   expect(negativeSummaryTree).toMatchSnapshot();
+
+  // Expect negative with uncovered_count >= thresholdUncovered
+  const negativeSummaryUncoveredProps = {
+    coverageSummaryData: {...FLOW_COVERAGE_SUMMARY_DATA, uncoveredThreshold: 4}
+  };
+  const negativeSummaryUncoveredTree = renderer.create(<FlowCoverageSummaryTable {...negativeSummaryUncoveredProps}/>).toJSON();
+  expect(negativeSummaryUncoveredTree).toMatchSnapshot();
 });
 
 test.skip('<FlowCoverageSummaryTable /> with missing props');

src/__tests__/test-flow.js

@@ -430,6 +430,7 @@ const testCollectFlowCoverage = async ({
     globIncludePatterns,
     globExcludePatterns,
     threshold: 80,
+    thresholdUncovered: 3,
     concurrentFiles: 5,
     strictCoverage,
     excludeNonFlow
@@ -462,6 +463,7 @@ const testCollectFlowCoverage = async ({
     concurrentFiles: 5,
     percent: 50,
     threshold: 80,
+    thresholdUncovered: 3,
     /* eslint-disable camelcase */
     covered_count: excludeNonFlow ? 4 : 5,
     uncovered_count: excludeNonFlow ? 4 : 5,

src/__tests__/test-index.js

@@ -116,4 +116,14 @@ it('generateFlowCoverageReport', async () => {
   expect(exception3 && exception3.message).toMatch(
     /empty globIncludePatterns option/
   );
+
+  let exception4;
+  try {
+    await generateFlowCoverageReport({...options, threshold: undefined, thresholdUncovered: undefined});
+  } catch (err) {
+    exception4 = err;
+  }
+  expect(exception4 && exception4.message).toMatch(
+    /threshold or thresholdUncovered option is mandatory/
+  );
 });

src/lib/cli/args.js

@@ -73,6 +73,10 @@ export default function processArgv(argv: Array<string>): any {
       type: 'number',
       describe: `the minimum coverage percent requested (defaults to ${defaultConfig.threshold})`
     })
+    .options('threshold-uncovered', {
+      type: 'number',
+      describe: `the maximum number of uncovered lines`
+    })
     .options('percent-decimals', {
       alias: ['percentDecimanls'],
       type: 'number',

src/lib/cli/config.js

@@ -19,6 +19,7 @@ export type ConfigParams = {|
   globExcludePatterns?: Array<string>,
   globIncludePatterns: Array<string>,
   threshold: number,
+  thresholdUncovered: number,
   percentDecimals: number,
   outputDir: string,
   concurrentFiles?: number,
@@ -58,11 +59,12 @@ export const defaultConfig: DefaultConfigParams = {
   projectDir: path.resolve(process.cwd()),
   globExcludePatterns: ['node_modules/**'],
   globIncludePatterns: [],
-  threshold: 80,
   percentDecimals: 0,
   outputDir: './flow-coverage',
   concurrentFiles: 1,
   strictCoverage: false,
+  threshold: 80,
+  thresholdUncovered: 0,
   excludeNonFlow: false,
   noConfig: false,
   htmlTemplateOptions: {

src/lib/cli/index.js

@@ -20,7 +20,16 @@ exports.run = () => {
   }
 
   generateFlowCoverageReport({...args}).then(([coverageSummaryData]) => {
-    const {percent, threshold} = coverageSummaryData;
+    /* eslint-disable camelcase */
+    const {percent, threshold, thresholdUncovered, uncovered_count} = coverageSummaryData;
+
+    if (uncovered_count > thresholdUncovered) {
+    /* eslint-enable camelcase */
+      console.error(
+        `Flow Coverage uncovered count is higher than the uncoveredThreshold`
+      );
+      process.exit(2); // eslint-disable-line unicorn/no-process-exit
+    }
     if (percent < threshold) {
       console.error(
         `Flow Coverage ${percent}% is below the required threshold ${threshold}%`

src/lib/components/body-coverage-sourcefile.jsx

@@ -70,7 +70,7 @@ export default function HTMLReportBodySourceFile(props: FlowCoverageSourceFileRe
   }
   const {percent} = coverageData;
 
-  const threshold = coverageSummaryData.threshold;
+  const {threshold, thresholdUncovered} = coverageSummaryData;
 
   if (!threshold) {
     throw new Error('Missing threshold in coverageSummaryData');
@@ -84,9 +84,11 @@ export default function HTMLReportBodySourceFile(props: FlowCoverageSourceFileRe
 
   let meterBar;
 
+  /* eslint-disable camelcase */
   if (props.htmlTemplateOptions && props.htmlTemplateOptions.showMeterBar) {
-    meterBar = <FlowCoverageMeterBar percent={percent} threshold={threshold}/>;
+    meterBar = <FlowCoverageMeterBar percent={percent} threshold={threshold} thresholdUncovered={thresholdUncovered} uncoveredCount={uncovered_count}/>;
   }
+  /* eslint-enable camelcase */
 
   return (
     <body>
@@ -117,6 +119,7 @@ export default function HTMLReportBodySourceFile(props: FlowCoverageSourceFileRe
                   isFlow: coverageData.isFlow,
                   percent,
                   threshold,
+                  thresholdUncovered,
                   /* eslint-disable camelcase */
                   covered_count,
                   uncovered_count

src/lib/components/body-coverage-summary.jsx

@@ -44,6 +44,7 @@ export default function HTMLReportBodySummary(props: FlowCoverageSummaryReportPr
               flowCoverageStderr: fileSummary.flowCoverageStderr,
               disableLink: false,
               threshold: summary.threshold,
+              thresholdUncovered: summary.thresholdUncovered,
               annotation: fileSummary.annotation,
               percent: fileSummary.percent,
               /* eslint-disable camelcase */
@@ -61,7 +62,14 @@ export default function HTMLReportBodySummary(props: FlowCoverageSummaryReportPr
   let meterBar;
 
   if (props.htmlTemplateOptions && props.htmlTemplateOptions.showMeterBar) {
-    meterBar = <FlowCoverageMeterBar percent={percent} threshold={summary.threshold}/>;
+    meterBar = (
+      <FlowCoverageMeterBar
+        percent={percent}
+        threshold={summary.threshold}
+        thresholdUncovered={summary.thresholdUncovered}
+        uncoveredCount={summary.uncovered_count}
+        />
+    );
   }
 
   return (

src/lib/components/coverage-file-table-row.jsx

@@ -19,6 +19,7 @@ export default function FlowCoverageFileTableRow(
     percent: number,
     disableLink: boolean,
     threshold: number,
+    thresholdUncovered: number,
     isError: boolean,
     isFlow: boolean,
     flowCoverageError: ?string,
@@ -37,10 +38,18 @@ export default function FlowCoverageFileTableRow(
     isError,
     isFlow,
     disableLink,
-    threshold
+    threshold,
+    thresholdUncovered
   } = props;
 
-  const aboveThreshold = percent >= threshold;
+  let aboveThreshold;
+
+  if (thresholdUncovered) {
+    aboveThreshold = uncovered_count <= thresholdUncovered;
+  } else {
+    aboveThreshold = percent >= threshold;
+  }
+
   let className = (!isError && isFlow && aboveThreshold) ?
     'positive' : 'negative';
 

src/lib/components/coverage-meter-bar.jsx

@@ -5,10 +5,27 @@
 import React from 'react';
 
 export default function FlowCoverageMeterBar(
-  props: {percent: number, threshold: number}
+  props: {
+    percent: number,
+    threshold: number,
+    thresholdUncovered: number,
+    uncoveredCount: number
+  }
 ) {
-  const threshold = props.threshold;
-  const color = props.percent >= threshold ? 'green' : 'red';
+  const {
+    threshold,
+    thresholdUncovered,
+    uncoveredCount,
+    percent
+  } = props;
+
+  let color;
+  if (thresholdUncovered) {
+    color = uncoveredCount <= thresholdUncovered ? 'green' : 'red';
+  } else {
+    color = percent >= threshold ? 'green' : 'red';
+  }
+
   const style = {
     padding: 0, height: 12
   };

src/lib/components/coverage-summary-table.jsx

@@ -12,7 +12,14 @@ export default function FlowCoverageSummaryTable(props: FlowCoverageSummaryRepor
   }
   const summary = props.coverageSummaryData;
   const percent = summary.percent;
-  const className = percent >= summary.threshold ? 'positive' : 'negative';
+  const threshold = summary.thresholdUncovered || summary.threshold;
+  let className;
+
+  if (summary.thresholdUncovered) {
+    className = summary.uncovered_count <= threshold ? 'positive' : 'negative';
+  } else {
+    className = percent >= threshold ? 'positive' : 'negative';
+  }
 
   return (
     <table className="ui small celled table">

src/lib/flow.js

@@ -328,6 +328,7 @@ export type FlowCoverageSummaryData = {
   uncovered_count: number,
   percent: number,
   threshold: number,
+  thresholdUncovered: number,
   strictCoverage: boolean,
   generatedAt: string,
   flowStatus: FlowStatus,
@@ -387,6 +388,7 @@ export function collectFlowCoverage(
     globIncludePatterns,
     globExcludePatterns = [],
     threshold,
+    thresholdUncovered,
     percentDecimals,
     concurrentFiles = 1,
     strictCoverage,
@@ -407,6 +409,7 @@ export function collectFlowCoverage(
 
     const coverageSummaryData: FlowCoverageSummaryData = {
       threshold,
+      thresholdUncovered,
       covered_count: 0, uncovered_count: 0, // eslint-disable-line camelcase
       percent: 0,
       generatedAt: coverageGeneratedAt,

src/lib/index.js

@@ -66,8 +66,8 @@ export default async function generateFlowCoverageReport(opts: FlowCoverageRepor
     return Promise.reject(new TypeError('empty globIncludePatterns option'));
   }
 
-  if (!opts.threshold) {
-    return Promise.reject(new TypeError('threshold option is mandatory'));
+  if (!opts.threshold && !opts.thresholdUncovered) {
+    return Promise.reject(new TypeError('threshold or thresholdUncovered option is mandatory'));
   }
 
   const coverageData: FlowCoverageSummaryData = await collectFlowCoverage(