Files
atom/src/typescript.coffee
Kevin Sawicki a70be30ee7 🎨
2015-03-26 14:37:30 -07:00

107 lines
2.9 KiB
CoffeeScript

###
Cache for source code transpiled by TypeScript.
Inspired by https://github.com/atom/atom/blob/7a719d585db96ff7d2977db9067e1d9d4d0adf1a/src/babel.coffee
###
crypto = require 'crypto'
fs = require 'fs-plus'
path = require 'path'
tss = null # Defer until used
stats =
hits: 0
misses: 0
defaultOptions =
target: 1 # ES5
module: 'commonjs'
sourceMap: true
createTypeScriptVersionAndOptionsDigest = (version, options) ->
shasum = crypto.createHash('sha1')
# Include the version of typescript in the hash.
shasum.update('typescript', 'utf8')
shasum.update('\0', 'utf8')
shasum.update(version, 'utf8')
shasum.update('\0', 'utf8')
shasum.update(JSON.stringify(options))
shasum.digest('hex')
cacheDir = null
jsCacheDir = null
getCachePath = (sourceCode) ->
digest = crypto.createHash('sha1').update(sourceCode, 'utf8').digest('hex')
unless jsCacheDir?
tssVersion = require('typescript-simple/package.json').version
jsCacheDir = path.join(cacheDir, createTypeScriptVersionAndOptionsDigest(tssVersion, defaultOptions))
path.join(jsCacheDir, "#{digest}.js")
getCachedJavaScript = (cachePath) ->
if fs.isFileSync(cachePath)
try
cachedJavaScript = fs.readFileSync(cachePath, 'utf8')
stats.hits++
return cachedJavaScript
null
# Returns the TypeScript options that should be used to transpile filePath.
createOptions = (filePath) ->
options = filename: filePath
for key, value of defaultOptions
options[key] = value
options
transpile = (sourceCode, filePath, cachePath) ->
options = createOptions(filePath)
unless tss?
{TypeScriptSimple} = require 'typescript-simple'
tss = new TypeScriptSimple(options, false)
js = tss.compile(sourceCode, filePath)
stats.misses++
try
fs.writeFileSync(cachePath, js)
js
# Function that obeys the contract of an entry in the require.extensions map.
# Returns the transpiled version of the JavaScript code at filePath, which is
# either generated on the fly or pulled from cache.
loadFile = (module, filePath) ->
sourceCode = fs.readFileSync(filePath, 'utf8')
cachePath = getCachePath(sourceCode)
js = getCachedJavaScript(cachePath) ? transpile(sourceCode, filePath, cachePath)
module._compile(js, filePath)
register = ->
Object.defineProperty(require.extensions, '.ts', {
enumerable: true
writable: false
value: loadFile
})
setCacheDirectory = (newCacheDir) ->
if cacheDir isnt newCacheDir
cacheDir = newCacheDir
jsCacheDir = null
module.exports =
register: register
setCacheDirectory: setCacheDirectory
getCacheMisses: -> stats.misses
getCacheHits: -> stats.hits
# Visible for testing.
createTypeScriptVersionAndOptionsDigest: createTypeScriptVersionAndOptionsDigest
addPathToCache: (filePath) ->
return if path.extname(filePath) isnt '.ts'
sourceCode = fs.readFileSync(filePath, 'utf8')
cachePath = getCachePath(sourceCode)
transpile(sourceCode, filePath, cachePath)