Index: frontend/node_modules/v8-to-istanbul/lib/branch.js
===================================================================
--- frontend/node_modules/v8-to-istanbul/lib/branch.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/v8-to-istanbul/lib/branch.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,28 @@
+module.exports = class CovBranch {
+  constructor (startLine, startCol, endLine, endCol, count) {
+    this.startLine = startLine
+    this.startCol = startCol
+    this.endLine = endLine
+    this.endCol = endCol
+    this.count = count
+  }
+
+  toIstanbul () {
+    const location = {
+      start: {
+        line: this.startLine,
+        column: this.startCol
+      },
+      end: {
+        line: this.endLine,
+        column: this.endCol
+      }
+    }
+    return {
+      type: 'branch',
+      line: this.startLine,
+      loc: location,
+      locations: [Object.assign({}, location)]
+    }
+  }
+}
Index: frontend/node_modules/v8-to-istanbul/lib/function.js
===================================================================
--- frontend/node_modules/v8-to-istanbul/lib/function.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/v8-to-istanbul/lib/function.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,29 @@
+module.exports = class CovFunction {
+  constructor (name, startLine, startCol, endLine, endCol, count) {
+    this.name = name
+    this.startLine = startLine
+    this.startCol = startCol
+    this.endLine = endLine
+    this.endCol = endCol
+    this.count = count
+  }
+
+  toIstanbul () {
+    const loc = {
+      start: {
+        line: this.startLine,
+        column: this.startCol
+      },
+      end: {
+        line: this.endLine,
+        column: this.endCol
+      }
+    }
+    return {
+      name: this.name,
+      decl: loc,
+      loc: loc,
+      line: this.startLine
+    }
+  }
+}
Index: frontend/node_modules/v8-to-istanbul/lib/line.js
===================================================================
--- frontend/node_modules/v8-to-istanbul/lib/line.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/v8-to-istanbul/lib/line.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,34 @@
+module.exports = class CovLine {
+  constructor (line, startCol, lineStr) {
+    this.line = line
+    // note that startCol and endCol are absolute positions
+    // within a file, not relative to the line.
+    this.startCol = startCol
+
+    // the line length itself does not include the newline characters,
+    // these are however taken into account when enumerating absolute offset.
+    const matchedNewLineChar = lineStr.match(/\r?\n$/u)
+    const newLineLength = matchedNewLineChar ? matchedNewLineChar[0].length : 0
+    this.endCol = startCol + lineStr.length - newLineLength
+
+    // we start with all lines having been executed, and work
+    // backwards zeroing out lines based on V8 output.
+    this.count = 1
+
+    // set by source.js during parsing, if /* c8 ignore next */ is found.
+    this.ignore = false
+  }
+
+  toIstanbul () {
+    return {
+      start: {
+        line: this.line,
+        column: 0
+      },
+      end: {
+        line: this.line,
+        column: this.endCol - this.startCol
+      }
+    }
+  }
+}
Index: frontend/node_modules/v8-to-istanbul/lib/range.js
===================================================================
--- frontend/node_modules/v8-to-istanbul/lib/range.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/v8-to-istanbul/lib/range.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,33 @@
+/**
+ * ...something resembling a binary search, to find the lowest line within the range.
+ * And then you could break as soon as the line is longer than the range...
+ */
+module.exports.sliceRange = (lines, startCol, endCol, inclusive = false) => {
+  let start = 0
+  let end = lines.length - 1
+
+  /**
+   * I consider this a temporary solution until I find an alternaive way to fix the "off by one issue"
+   */
+  const extStartCol = inclusive ? startCol - 1 : startCol
+
+  while (start < end) {
+    const mid = (start + end) >> 1
+    if (lines[mid].startCol <= startCol && lines[mid].endCol > extStartCol) {
+      start = mid
+      end = start
+    } else if (lines[mid].startCol > startCol) {
+      end = mid - 1
+    } else {
+      start = mid + 1
+    }
+  }
+  if (start === end) {
+    while (end < lines.length && extStartCol < lines[end].endCol && endCol >= lines[end].startCol) {
+      ++end
+    }
+    return lines.slice(start, end)
+  } else {
+    return []
+  }
+}
Index: frontend/node_modules/v8-to-istanbul/lib/source.js
===================================================================
--- frontend/node_modules/v8-to-istanbul/lib/source.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/v8-to-istanbul/lib/source.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,245 @@
+const CovLine = require('./line')
+const { sliceRange } = require('./range')
+const { GREATEST_LOWER_BOUND, LEAST_UPPER_BOUND } = require('source-map').SourceMapConsumer
+
+module.exports = class CovSource {
+  constructor (sourceRaw, wrapperLength) {
+    sourceRaw = sourceRaw ? sourceRaw.trimEnd() : ''
+    this.lines = []
+    this.eof = sourceRaw.length
+    this.shebangLength = getShebangLength(sourceRaw)
+    this.wrapperLength = wrapperLength - this.shebangLength
+    this._buildLines(sourceRaw)
+  }
+
+  _buildLines (source) {
+    let position = 0
+    let ignoreCount = 0
+    let ignoreAll = false
+    for (const [i, lineStr] of source.split(/(?<=\r?\n)/u).entries()) {
+      const line = new CovLine(i + 1, position, lineStr)
+      if (ignoreCount > 0) {
+        line.ignore = true
+        ignoreCount--
+      } else if (ignoreAll) {
+        line.ignore = true
+      }
+      this.lines.push(line)
+      position += lineStr.length
+
+      const ignoreToken = this._parseIgnore(lineStr)
+      if (!ignoreToken) continue
+
+      line.ignore = true
+      if (ignoreToken.count !== undefined) {
+        ignoreCount = ignoreToken.count
+      }
+      if (ignoreToken.start || ignoreToken.stop) {
+        ignoreAll = ignoreToken.start
+        ignoreCount = 0
+      }
+    }
+  }
+
+  /**
+   * Parses for comments:
+   *    c8 ignore next
+   *    c8 ignore next 3
+   *    c8 ignore start
+   *    c8 ignore stop
+   * @param {string} lineStr
+   * @return {{count?: number, start?: boolean, stop?: boolean}|undefined}
+   */
+  _parseIgnore (lineStr) {
+    const testIgnoreNextLines = lineStr.match(/^\W*\/\* c8 ignore next (?<count>[0-9]+) *\*\/\W*$/)
+    if (testIgnoreNextLines) {
+      return { count: Number(testIgnoreNextLines.groups.count) }
+    }
+
+    // Check if comment is on its own line.
+    if (lineStr.match(/^\W*\/\* c8 ignore next *\*\/\W*$/)) {
+      return { count: 1 }
+    }
+
+    if (lineStr.match(/\/\* c8 ignore next \*\//)) {
+      // Won't ignore successive lines, but the current line will be ignored.
+      return { count: 0 }
+    }
+
+    const testIgnoreStartStop = lineStr.match(/\/\* c8 ignore (?<mode>start|stop) *\*\//)
+    if (testIgnoreStartStop) {
+      if (testIgnoreStartStop.groups.mode === 'start') return { start: true }
+      if (testIgnoreStartStop.groups.mode === 'stop') return { stop: true }
+    }
+  }
+
+  // given a start column and end column in absolute offsets within
+  // a source file (0 - EOF), returns the relative line column positions.
+  offsetToOriginalRelative (sourceMap, startCol, endCol) {
+    const lines = sliceRange(this.lines, startCol, endCol, true)
+    if (!lines.length) return {}
+
+    const start = originalPositionTryBoth(
+      sourceMap,
+      lines[0].line,
+      Math.max(0, startCol - lines[0].startCol)
+    )
+    if (!(start && start.source)) {
+      return {}
+    }
+
+    let end = originalEndPositionFor(
+      sourceMap,
+      lines[lines.length - 1].line,
+      endCol - lines[lines.length - 1].startCol
+    )
+    if (!(end && end.source)) {
+      return {}
+    }
+
+    if (start.source !== end.source) {
+      return {}
+    }
+
+    if (start.line === end.line && start.column === end.column) {
+      end = sourceMap.originalPositionFor({
+        line: lines[lines.length - 1].line,
+        column: endCol - lines[lines.length - 1].startCol,
+        bias: LEAST_UPPER_BOUND
+      })
+      end.column -= 1
+    }
+
+    return {
+      source: start.source,
+      startLine: start.line,
+      relStartCol: start.column,
+      endLine: end.line,
+      relEndCol: end.column
+    }
+  }
+
+  relativeToOffset (line, relCol) {
+    line = Math.max(line, 1)
+    if (this.lines[line - 1] === undefined) return this.eof
+    return Math.min(this.lines[line - 1].startCol + relCol, this.lines[line - 1].endCol)
+  }
+}
+
+// this implementation is pulled over from istanbul-lib-sourcemap:
+// https://github.com/istanbuljs/istanbuljs/blob/master/packages/istanbul-lib-source-maps/lib/get-mapping.js
+//
+/**
+ * AST ranges are inclusive for start positions and exclusive for end positions.
+ * Source maps are also logically ranges over text, though interacting with
+ * them is generally achieved by working with explicit positions.
+ *
+ * When finding the _end_ location of an AST item, the range behavior is
+ * important because what we're asking for is the _end_ of whatever range
+ * corresponds to the end location we seek.
+ *
+ * This boils down to the following steps, conceptually, though the source-map
+ * library doesn't expose primitives to do this nicely:
+ *
+ * 1. Find the range on the generated file that ends at, or exclusively
+ *    contains the end position of the AST node.
+ * 2. Find the range on the original file that corresponds to
+ *    that generated range.
+ * 3. Find the _end_ location of that original range.
+ */
+function originalEndPositionFor (sourceMap, line, column) {
+  // Given the generated location, find the original location of the mapping
+  // that corresponds to a range on the generated file that overlaps the
+  // generated file end location. Note however that this position on its
+  // own is not useful because it is the position of the _start_ of the range
+  // on the original file, and we want the _end_ of the range.
+  const beforeEndMapping = originalPositionTryBoth(
+    sourceMap,
+    line,
+    Math.max(column - 1, 1)
+  )
+
+  if (beforeEndMapping.source === null) {
+    return null
+  }
+
+  // Convert that original position back to a generated one, with a bump
+  // to the right, and a rightward bias. Since 'generatedPositionFor' searches
+  // for mappings in the original-order sorted list, this will find the
+  // mapping that corresponds to the one immediately after the
+  // beforeEndMapping mapping.
+  const afterEndMapping = sourceMap.generatedPositionFor({
+    source: beforeEndMapping.source,
+    line: beforeEndMapping.line,
+    column: beforeEndMapping.column + 1,
+    bias: LEAST_UPPER_BOUND
+  })
+  if (
+  // If this is null, it means that we've hit the end of the file,
+  // so we can use Infinity as the end column.
+    afterEndMapping.line === null ||
+      // If these don't match, it means that the call to
+      // 'generatedPositionFor' didn't find any other original mappings on
+      // the line we gave, so consider the binding to extend to infinity.
+      sourceMap.originalPositionFor(afterEndMapping).line !==
+          beforeEndMapping.line
+  ) {
+    return {
+      source: beforeEndMapping.source,
+      line: beforeEndMapping.line,
+      column: Infinity
+    }
+  }
+
+  // Convert the end mapping into the real original position.
+  return sourceMap.originalPositionFor(afterEndMapping)
+}
+
+function originalPositionTryBoth (sourceMap, line, column) {
+  let original = sourceMap.originalPositionFor({
+    line,
+    column,
+    bias: GREATEST_LOWER_BOUND
+  })
+  if (original.line === null) {
+    original = sourceMap.originalPositionFor({
+      line,
+      column,
+      bias: LEAST_UPPER_BOUND
+    })
+  }
+  // The source maps generated by https://github.com/istanbuljs/istanbuljs
+  // (using @babel/core 7.7.5) have behavior, such that a mapping
+  // mid-way through a line maps to an earlier line than a mapping
+  // at position 0. Using the line at positon 0 seems to provide better reports:
+  //
+  //     if (true) {
+  //        cov_y5divc6zu().b[1][0]++;
+  //        cov_y5divc6zu().s[3]++;
+  //        console.info('reachable');
+  //     }  else { ... }
+  //  ^  ^
+  // l5  l3
+  const min = sourceMap.originalPositionFor({
+    line,
+    column: 0,
+    bias: GREATEST_LOWER_BOUND
+  })
+  if (min.line > original.line) {
+    original = min
+  }
+  return original
+}
+
+// Not required since Node 12, see: https://github.com/nodejs/node/pull/27375
+const isPreNode12 = /^v1[0-1]\./u.test(process.version)
+function getShebangLength (source) {
+  if (isPreNode12 && source.indexOf('#!') === 0) {
+    const match = source.match(/(?<shebang>#!.*)/)
+    if (match) {
+      return match.groups.shebang.length
+    }
+  } else {
+    return 0
+  }
+}
Index: frontend/node_modules/v8-to-istanbul/lib/v8-to-istanbul.js
===================================================================
--- frontend/node_modules/v8-to-istanbul/lib/v8-to-istanbul.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/v8-to-istanbul/lib/v8-to-istanbul.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,318 @@
+const assert = require('assert')
+const convertSourceMap = require('convert-source-map')
+const util = require('util')
+const debuglog = util.debuglog('c8')
+const { dirname, isAbsolute, join, resolve } = require('path')
+const { fileURLToPath } = require('url')
+const CovBranch = require('./branch')
+const CovFunction = require('./function')
+const CovSource = require('./source')
+const { sliceRange } = require('./range')
+const compatError = Error(`requires Node.js ${require('../package.json').engines.node}`)
+let readFile = () => { throw compatError }
+try {
+  readFile = require('fs').promises.readFile
+} catch (_err) {
+  // most likely we're on an older version of Node.js.
+}
+const { SourceMapConsumer } = require('source-map')
+const isOlderNode10 = /^v10\.(([0-9]\.)|(1[0-5]\.))/u.test(process.version)
+const isNode8 = /^v8\./.test(process.version)
+
+// Injected when Node.js is loading script into isolate pre Node 10.16.x.
+// see: https://github.com/nodejs/node/pull/21573.
+const cjsWrapperLength = isOlderNode10 ? require('module').wrapper[0].length : 0
+
+module.exports = class V8ToIstanbul {
+  constructor (scriptPath, wrapperLength, sources, excludePath) {
+    assert(typeof scriptPath === 'string', 'scriptPath must be a string')
+    assert(!isNode8, 'This module does not support node 8 or lower, please upgrade to node 10')
+    this.path = parsePath(scriptPath)
+    this.wrapperLength = wrapperLength === undefined ? cjsWrapperLength : wrapperLength
+    this.excludePath = excludePath || (() => false)
+    this.sources = sources || {}
+    this.generatedLines = []
+    this.branches = {}
+    this.functions = {}
+    this.covSources = []
+    this.rawSourceMap = undefined
+    this.sourceMap = undefined
+    this.sourceTranspiled = undefined
+    // Indicate that this report was generated with placeholder data from
+    // running --all:
+    this.all = false
+  }
+
+  async load () {
+    const rawSource = this.sources.source || await readFile(this.path, 'utf8')
+    this.rawSourceMap = this.sources.sourceMap ||
+      // if we find a source-map (either inline, or a .map file) we load
+      // both the transpiled and original source, both of which are used during
+      // the backflips we perform to remap absolute to relative positions.
+      convertSourceMap.fromSource(rawSource) || convertSourceMap.fromMapFileSource(rawSource, dirname(this.path))
+
+    if (this.rawSourceMap) {
+      if (this.rawSourceMap.sourcemap.sources.length > 1) {
+        this.sourceMap = await new SourceMapConsumer(this.rawSourceMap.sourcemap)
+        if (!this.sourceMap.sourcesContent) {
+          this.sourceMap.sourcesContent = await this.sourcesContentFromSources()
+        }
+        this.covSources = this.sourceMap.sourcesContent.map((rawSource, i) => ({ source: new CovSource(rawSource, this.wrapperLength), path: this.sourceMap.sources[i] }))
+        this.sourceTranspiled = new CovSource(rawSource, this.wrapperLength)
+      } else {
+        const candidatePath = this.rawSourceMap.sourcemap.sources.length >= 1 ? this.rawSourceMap.sourcemap.sources[0] : this.rawSourceMap.sourcemap.file
+        this.path = this._resolveSource(this.rawSourceMap, candidatePath || this.path)
+        this.sourceMap = await new SourceMapConsumer(this.rawSourceMap.sourcemap)
+
+        let originalRawSource
+        if (this.sources.sourceMap && this.sources.sourceMap.sourcemap && this.sources.sourceMap.sourcemap.sourcesContent && this.sources.sourceMap.sourcemap.sourcesContent.length === 1) {
+          // If the sourcesContent field has been provided, return it rather than attempting
+          // to load the original source from disk.
+          // TODO: investigate whether there's ever a case where we hit this logic with 1:many sources.
+          originalRawSource = this.sources.sourceMap.sourcemap.sourcesContent[0]
+        } else if (this.sources.originalSource) {
+          // Original source may be populated on the sources object.
+          originalRawSource = this.sources.originalSource
+        } else if (this.sourceMap.sourcesContent && this.sourceMap.sourcesContent[0]) {
+          // perhaps we loaded sourcesContent was populated by an inline source map, or .map file?
+          // TODO: investigate whether there's ever a case where we hit this logic with 1:many sources.
+          originalRawSource = this.sourceMap.sourcesContent[0]
+        } else {
+          // We fallback to reading the original source from disk.
+          originalRawSource = await readFile(this.path, 'utf8')
+        }
+        this.covSources = [{ source: new CovSource(originalRawSource, this.wrapperLength), path: this.path }]
+        this.sourceTranspiled = new CovSource(rawSource, this.wrapperLength)
+      }
+    } else {
+      this.covSources = [{ source: new CovSource(rawSource, this.wrapperLength), path: this.path }]
+    }
+  }
+
+  async sourcesContentFromSources () {
+    const fileList = this.sourceMap.sources.map(relativePath => {
+      const realPath = this._resolveSource(this.rawSourceMap, relativePath)
+      return readFile(realPath, 'utf-8')
+        .then(result => result)
+        .catch(err => {
+          debuglog(`failed to load ${realPath}: ${err.message}`)
+        })
+    })
+    return await Promise.all(fileList)
+  }
+
+  destroy () {
+    if (this.sourceMap) {
+      this.sourceMap.destroy()
+      this.sourceMap = undefined
+    }
+  }
+
+  _resolveSource (rawSourceMap, sourcePath) {
+    if (sourcePath.startsWith('file://')) {
+      return fileURLToPath(sourcePath)
+    }
+    sourcePath = sourcePath.replace(/^webpack:\/\//, '')
+    const sourceRoot = rawSourceMap.sourcemap.sourceRoot ? rawSourceMap.sourcemap.sourceRoot.replace('file://', '') : ''
+    const candidatePath = join(sourceRoot, sourcePath)
+
+    if (isAbsolute(candidatePath)) {
+      return candidatePath
+    } else {
+      return resolve(dirname(this.path), candidatePath)
+    }
+  }
+
+  applyCoverage (blocks) {
+    blocks.forEach(block => {
+      block.ranges.forEach((range, i) => {
+        const { startCol, endCol, path, covSource } = this._maybeRemapStartColEndCol(range)
+        if (this.excludePath(path)) {
+          return
+        }
+        let lines
+        if (block.functionName === '(empty-report)') {
+          // (empty-report), this will result in a report that has all lines zeroed out.
+          lines = covSource.lines.filter((line) => {
+            line.count = 0
+            return true
+          })
+          this.all = lines.length > 0
+        } else {
+          lines = sliceRange(covSource.lines, startCol, endCol)
+        }
+        if (!lines.length) {
+          return
+        }
+
+        const startLineInstance = lines[0]
+        const endLineInstance = lines[lines.length - 1]
+
+        if (block.isBlockCoverage) {
+          this.branches[path] = this.branches[path] || []
+          // record branches.
+          this.branches[path].push(new CovBranch(
+            startLineInstance.line,
+            startCol - startLineInstance.startCol,
+            endLineInstance.line,
+            endCol - endLineInstance.startCol,
+            range.count
+          ))
+
+          // if block-level granularity is enabled, we still create a single
+          // CovFunction tracking object for each set of ranges.
+          if (block.functionName && i === 0) {
+            this.functions[path] = this.functions[path] || []
+            this.functions[path].push(new CovFunction(
+              block.functionName,
+              startLineInstance.line,
+              startCol - startLineInstance.startCol,
+              endLineInstance.line,
+              endCol - endLineInstance.startCol,
+              range.count
+            ))
+          }
+        } else if (block.functionName) {
+          this.functions[path] = this.functions[path] || []
+          // record functions.
+          this.functions[path].push(new CovFunction(
+            block.functionName,
+            startLineInstance.line,
+            startCol - startLineInstance.startCol,
+            endLineInstance.line,
+            endCol - endLineInstance.startCol,
+            range.count
+          ))
+        }
+
+        // record the lines (we record these as statements, such that we're
+        // compatible with Istanbul 2.0).
+        lines.forEach(line => {
+          // make sure branch spans entire line; don't record 'goodbye'
+          // branch in `const foo = true ? 'hello' : 'goodbye'` as a
+          // 0 for line coverage.
+          //
+          // All lines start out with coverage of 1, and are later set to 0
+          // if they are not invoked; line.ignore prevents a line from being
+          // set to 0, and is set if the special comment /* c8 ignore next */
+          // is used.
+
+          if (startCol <= line.startCol && endCol >= line.endCol && !line.ignore) {
+            line.count = range.count
+          }
+        })
+      })
+    })
+  }
+
+  _maybeRemapStartColEndCol (range) {
+    let covSource = this.covSources[0].source
+    let startCol = Math.max(0, range.startOffset - covSource.wrapperLength)
+    let endCol = Math.min(covSource.eof, range.endOffset - covSource.wrapperLength)
+    let path = this.path
+
+    if (this.sourceMap) {
+      startCol = Math.max(0, range.startOffset - this.sourceTranspiled.wrapperLength)
+      endCol = Math.min(this.sourceTranspiled.eof, range.endOffset - this.sourceTranspiled.wrapperLength)
+
+      const { startLine, relStartCol, endLine, relEndCol, source } = this.sourceTranspiled.offsetToOriginalRelative(
+        this.sourceMap,
+        startCol,
+        endCol
+      )
+
+      const matchingSource = this.covSources.find(covSource => covSource.path === source)
+      covSource = matchingSource ? matchingSource.source : this.covSources[0].source
+      path = matchingSource ? matchingSource.path : this.covSources[0].path
+
+      // next we convert these relative positions back to absolute positions
+      // in the original source (which is the format expected in the next step).
+      startCol = covSource.relativeToOffset(startLine, relStartCol)
+      endCol = covSource.relativeToOffset(endLine, relEndCol)
+    }
+
+    return {
+      path,
+      covSource,
+      startCol,
+      endCol
+    }
+  }
+
+  getInnerIstanbul (source, path) {
+    // We apply the "Resolving Sources" logic (as defined in
+    // sourcemaps.info/spec.html) as a final step for 1:many source maps.
+    // for 1:1 source maps, the resolve logic is applied while loading.
+    //
+    // TODO: could we move the resolving logic for 1:1 source maps to the final
+    // step as well? currently this breaks some tests in c8.
+    let resolvedPath = path
+    if (this.rawSourceMap && this.rawSourceMap.sourcemap.sources.length > 1) {
+      resolvedPath = this._resolveSource(this.rawSourceMap, path)
+    }
+
+    if (this.excludePath(resolvedPath)) {
+      return
+    }
+
+    return {
+      [resolvedPath]: {
+        path: resolvedPath,
+        all: this.all,
+        ...this._statementsToIstanbul(source, path),
+        ...this._branchesToIstanbul(source, path),
+        ...this._functionsToIstanbul(source, path)
+      }
+    }
+  }
+
+  toIstanbul () {
+    return this.covSources.reduce((istanbulOuter, { source, path }) => Object.assign(istanbulOuter, this.getInnerIstanbul(source, path)), {})
+  }
+
+  _statementsToIstanbul (source, path) {
+    const statements = {
+      statementMap: {},
+      s: {}
+    }
+    source.lines.forEach((line, index) => {
+      statements.statementMap[`${index}`] = line.toIstanbul()
+      statements.s[`${index}`] = line.count
+    })
+    return statements
+  }
+
+  _branchesToIstanbul (source, path) {
+    const branches = {
+      branchMap: {},
+      b: {}
+    }
+    this.branches[path] = this.branches[path] || []
+    this.branches[path].forEach((branch, index) => {
+      const srcLine = source.lines[branch.startLine - 1]
+      const ignore = srcLine === undefined ? true : srcLine.ignore
+      branches.branchMap[`${index}`] = branch.toIstanbul()
+      branches.b[`${index}`] = [ignore ? 1 : branch.count]
+    })
+    return branches
+  }
+
+  _functionsToIstanbul (source, path) {
+    const functions = {
+      fnMap: {},
+      f: {}
+    }
+    this.functions[path] = this.functions[path] || []
+    this.functions[path].forEach((fn, index) => {
+      const srcLine = source.lines[fn.startLine - 1]
+      const ignore = srcLine === undefined ? true : srcLine.ignore
+      functions.fnMap[`${index}`] = fn.toIstanbul()
+      functions.f[`${index}`] = ignore ? 1 : fn.count
+    })
+    return functions
+  }
+}
+
+function parsePath (scriptPath) {
+  return scriptPath.startsWith('file://') ? fileURLToPath(scriptPath) : scriptPath
+}