wallet-core/node_modules/concordance/lib/diff.js
2017-08-14 05:02:09 +02:00

392 lines
13 KiB
JavaScript

'use strict'
const constants = require('./constants')
const describe = require('./describe')
const lineBuilder = require('./lineBuilder')
const recursorUtils = require('./recursorUtils')
const shouldCompareDeep = require('./shouldCompareDeep')
const symbolProperties = require('./symbolProperties')
const themeUtils = require('./themeUtils')
const Circular = require('./Circular')
const Indenter = require('./Indenter')
const AMBIGUOUS = constants.AMBIGUOUS
const DEEP_EQUAL = constants.DEEP_EQUAL
const UNEQUAL = constants.UNEQUAL
const SHALLOW_EQUAL = constants.SHALLOW_EQUAL
const NOOP = Symbol('NOOP')
const alwaysFormat = () => true
function compareComplexShape (lhs, rhs) {
let result = lhs.compare(rhs)
if (result === DEEP_EQUAL) return DEEP_EQUAL
if (result === UNEQUAL || !shouldCompareDeep(result, lhs, rhs)) return UNEQUAL
let collectedSymbolProperties = false
let lhsRecursor = lhs.createRecursor()
let rhsRecursor = rhs.createRecursor()
do {
lhs = lhsRecursor()
rhs = rhsRecursor()
if (lhs === null && rhs === null) return SHALLOW_EQUAL
if (lhs === null || rhs === null) return UNEQUAL
result = lhs.compare(rhs)
if (result === UNEQUAL) return UNEQUAL
if (
result === AMBIGUOUS &&
lhs.isProperty === true && !collectedSymbolProperties &&
shouldCompareDeep(result, lhs, rhs)
) {
collectedSymbolProperties = true
const lhsCollector = new symbolProperties.Collector(lhs, lhsRecursor)
const rhsCollector = new symbolProperties.Collector(rhs, rhsRecursor)
lhsRecursor = recursorUtils.sequence(
lhsCollector.createRecursor(),
recursorUtils.unshift(lhsRecursor, lhsCollector.collectAll()))
rhsRecursor = recursorUtils.sequence(
rhsCollector.createRecursor(),
recursorUtils.unshift(rhsRecursor, rhsCollector.collectAll()))
}
} while (true)
}
function diffDescriptors (lhs, rhs, options) {
const theme = themeUtils.normalize(options)
const invert = options ? options.invert === true : false
const lhsCircular = new Circular()
const rhsCircular = new Circular()
const maxDepth = (options && options.maxDepth) || 0
let indent = new Indenter(0, ' ')
const lhsStack = []
const rhsStack = []
let topIndex = -1
const buffer = lineBuilder.buffer()
const diffStack = []
let diffIndex = -1
const isCircular = descriptor => lhsCircular.has(descriptor) || rhsCircular.has(descriptor)
const format = (builder, subject, circular) => {
if (diffIndex >= 0 && !diffStack[diffIndex].shouldFormat(subject)) return
if (circular.has(subject)) {
diffStack[diffIndex].formatter.append(builder.single(theme.circular))
return
}
const formatStack = []
let formatIndex = -1
do {
if (circular.has(subject)) {
formatStack[formatIndex].formatter.append(builder.single(theme.circular), subject)
} else {
let didFormat = false
if (typeof subject.formatDeep === 'function') {
let formatted = subject.formatDeep(themeUtils.applyModifiers(subject, theme), indent)
if (formatted !== null) {
didFormat = true
if (formatIndex === -1) {
formatted = builder.setDefaultGutter(formatted)
if (diffIndex === -1) {
buffer.append(formatted)
} else {
diffStack[diffIndex].formatter.append(formatted, subject)
}
} else {
formatStack[formatIndex].formatter.append(formatted, subject)
}
}
}
if (!didFormat && typeof subject.formatShallow === 'function') {
const formatter = subject.formatShallow(themeUtils.applyModifiers(subject, theme), indent)
const recursor = subject.createRecursor()
if (formatter.increaseIndent && maxDepth > 0 && indent.level === maxDepth) {
const isEmpty = recursor() === null
let formatted = !isEmpty && typeof formatter.maxDepth === 'function'
? formatter.maxDepth()
: formatter.finalize()
if (formatIndex === -1) {
formatted = builder.setDefaultGutter(formatted)
diffStack[diffIndex].formatter.append(formatted, subject)
} else {
formatStack[formatIndex].formatter.append(formatted, subject)
}
} else {
formatStack.push({
formatter,
recursor,
decreaseIndent: formatter.increaseIndent,
shouldFormat: formatter.shouldFormat || alwaysFormat,
subject
})
formatIndex++
if (formatter.increaseIndent) indent = indent.increase()
circular.add(subject)
}
}
}
while (formatIndex >= 0) {
do {
subject = formatStack[formatIndex].recursor()
} while (subject && !formatStack[formatIndex].shouldFormat(subject))
if (subject) {
break
}
const record = formatStack.pop()
formatIndex--
if (record.decreaseIndent) indent = indent.decrease()
circular.delete(record.subject)
let formatted = record.formatter.finalize()
if (formatIndex === -1) {
formatted = builder.setDefaultGutter(formatted)
if (diffIndex === -1) {
buffer.append(formatted)
} else {
diffStack[diffIndex].formatter.append(formatted, record.subject)
}
} else {
formatStack[formatIndex].formatter.append(formatted, record.subject)
}
}
} while (formatIndex >= 0)
}
do {
let compareResult = NOOP
if (lhsCircular.has(lhs)) {
compareResult = lhsCircular.get(lhs) === rhsCircular.get(rhs)
? DEEP_EQUAL
: UNEQUAL
} else if (rhsCircular.has(rhs)) {
compareResult = UNEQUAL
}
let firstPassSymbolProperty = false
if (lhs.isProperty === true) {
compareResult = lhs.compare(rhs)
if (compareResult === AMBIGUOUS) {
const parent = lhsStack[topIndex].subject
firstPassSymbolProperty = parent.isSymbolPropertiesCollector !== true && parent.isSymbolPropertiesComparable !== true
}
}
let didFormat = false
let mustRecurse = false
if (compareResult !== DEEP_EQUAL && !firstPassSymbolProperty && typeof lhs.prepareDiff === 'function') {
const lhsRecursor = topIndex === -1 ? null : lhsStack[topIndex].recursor
const rhsRecursor = topIndex === -1 ? null : rhsStack[topIndex].recursor
const instructions = lhs.prepareDiff(
rhs,
lhsRecursor,
rhsRecursor,
compareComplexShape,
isCircular)
if (instructions !== null) {
if (topIndex >= 0) {
if (typeof instructions.lhsRecursor === 'function') {
lhsStack[topIndex].recursor = instructions.lhsRecursor
}
if (typeof instructions.rhsRecursor === 'function') {
rhsStack[topIndex].recursor = instructions.rhsRecursor
}
}
if (instructions.compareResult) {
compareResult = instructions.compareResult
}
if (instructions.mustRecurse === true) {
mustRecurse = true
} else {
if (instructions.actualIsExtraneous === true) {
format(lineBuilder.actual, lhs, lhsCircular)
didFormat = true
} else if (instructions.multipleAreExtraneous === true) {
for (const extraneous of instructions.descriptors) {
format(lineBuilder.actual, extraneous, lhsCircular)
}
didFormat = true
} else if (instructions.expectedIsMissing === true) {
format(lineBuilder.expected, rhs, rhsCircular)
didFormat = true
} else if (instructions.multipleAreMissing === true) {
for (const missing of instructions.descriptors) {
format(lineBuilder.expected, missing, rhsCircular)
}
didFormat = true
} else if (instructions.isUnequal === true) {
format(lineBuilder.actual, lhs, lhsCircular)
format(lineBuilder.expected, rhs, rhsCircular)
didFormat = true
} else if (!instructions.compareResult) {
// TODO: Throw a useful, custom error
throw new Error('Illegal result of prepareDiff()')
}
}
}
}
if (!didFormat) {
if (compareResult === NOOP) {
compareResult = lhs.compare(rhs)
}
if (!mustRecurse) {
mustRecurse = shouldCompareDeep(compareResult, lhs, rhs)
}
if (compareResult === DEEP_EQUAL) {
format(lineBuilder, lhs, lhsCircular)
} else if (mustRecurse) {
if (compareResult === AMBIGUOUS && lhs.isProperty === true) {
// Replace both sides by a pseudo-descriptor which collects symbol
// properties instead.
lhs = new symbolProperties.Collector(lhs, lhsStack[topIndex].recursor)
rhs = new symbolProperties.Collector(rhs, rhsStack[topIndex].recursor)
// Replace the current recursors so they can continue correctly after
// the collectors have been "compared". This is necessary since the
// collectors eat the first value after the last symbol property.
lhsStack[topIndex].recursor = recursorUtils.unshift(lhsStack[topIndex].recursor, lhs.collectAll())
rhsStack[topIndex].recursor = recursorUtils.unshift(rhsStack[topIndex].recursor, rhs.collectAll())
}
if (typeof lhs.diffShallow === 'function') {
const formatter = lhs.diffShallow(rhs, themeUtils.applyModifiers(lhs, theme), indent)
diffStack.push({
formatter,
origin: lhs,
decreaseIndent: formatter.increaseIndent,
exceedsMaxDepth: formatter.increaseIndent && maxDepth > 0 && indent.level >= maxDepth,
shouldFormat: formatter.shouldFormat || alwaysFormat
})
diffIndex++
if (formatter.increaseIndent) indent = indent.increase()
} else if (typeof lhs.formatShallow === 'function') {
const formatter = lhs.formatShallow(themeUtils.applyModifiers(lhs, theme), indent)
diffStack.push({
formatter,
decreaseIndent: formatter.increaseIndent,
exceedsMaxDepth: formatter.increaseIndent && maxDepth > 0 && indent.level >= maxDepth,
shouldFormat: formatter.shouldFormat || alwaysFormat,
subject: lhs
})
diffIndex++
if (formatter.increaseIndent) indent = indent.increase()
}
lhsCircular.add(lhs)
rhsCircular.add(rhs)
lhsStack.push({ diffIndex, subject: lhs, recursor: lhs.createRecursor() })
rhsStack.push({ diffIndex, subject: rhs, recursor: rhs.createRecursor() })
topIndex++
} else {
const diffed = typeof lhs.diffDeep === 'function'
? lhs.diffDeep(rhs, themeUtils.applyModifiers(lhs, theme), indent)
: null
if (diffed === null) {
format(lineBuilder.actual, lhs, lhsCircular)
format(lineBuilder.expected, rhs, rhsCircular)
} else {
if (diffIndex === -1) {
buffer.append(diffed)
} else {
diffStack[diffIndex].formatter.append(diffed, lhs)
}
}
}
}
while (topIndex >= 0) {
lhs = lhsStack[topIndex].recursor()
rhs = rhsStack[topIndex].recursor()
if (lhs !== null && rhs !== null) {
break
}
if (lhs === null && rhs === null) {
const lhsRecord = lhsStack.pop()
const rhsRecord = rhsStack.pop()
lhsCircular.delete(lhsRecord.subject)
rhsCircular.delete(rhsRecord.subject)
topIndex--
if (lhsRecord.diffIndex === diffIndex) {
const record = diffStack.pop()
diffIndex--
if (record.decreaseIndent) indent = indent.decrease()
let formatted = record.formatter.finalize()
if (record.exceedsMaxDepth && !formatted.hasGutter) {
// The record exceeds the max depth, but contains no actual diff.
// Discard the potentially deep formatting and format just the
// original subject.
const subject = lhsRecord.subject
const formatter = subject.formatShallow(themeUtils.applyModifiers(subject, theme), indent)
const isEmpty = subject.createRecursor()() === null
formatted = !isEmpty && typeof formatter.maxDepth === 'function'
? formatter.maxDepth()
: formatter.finalize()
}
if (diffIndex === -1) {
buffer.append(formatted)
} else {
diffStack[diffIndex].formatter.append(formatted, record.subject)
}
}
} else {
let builder, circular, stack, subject
if (lhs === null) {
builder = lineBuilder.expected
circular = rhsCircular
stack = rhsStack
subject = rhs
} else {
builder = lineBuilder.actual
circular = lhsCircular
stack = lhsStack
subject = lhs
}
do {
format(builder, subject, circular)
subject = stack[topIndex].recursor()
} while (subject !== null)
}
}
} while (topIndex >= 0)
return buffer.toString({diff: true, invert, theme})
}
exports.diffDescriptors = diffDescriptors
function diff (actual, expected, options) {
return diffDescriptors(describe(actual, options), describe(expected, options), options)
}
exports.diff = diff