Proposed fix for the analyze step

This commit avoids the hardcoded use of the ./dist directory in the diff
anaysis step, instead using the directory specified via a new
--working_dir flag. Without this, the ./dist directory is always used
(if it exists, otherwise failure).

The "dist/dist/" repeat has also been removed because it should no
longer be required.

This commit could have used the `distDir` variable instead, but a new
"working_dir" flag has been introduced instead. A generic name has been
chosen to enable its use for things besides diff analysis later if
needed. It's possible that several files in "dist" could be moved there
later if they're not needed in the distribution, but this has not been
attempted here.

I feel a new directory is reasonable because the files associated with
the previous release don't naturally fit with "downloads" (i.e. files
from OSM) or "dist" (the new distribution). In Android in the future, we
may commit dist + download for change history, but committing the
previous release file seems redundant as it also lives in dist/ under a
previous commit.

The flags documentation has been adjusted to try to make the
distinctions between directories clearer.

.gitignore

@@ -87,4 +87,5 @@ $RECYCLE.BIN/
 # Project
 # =========================
 downloads
-dist
+working
+dist

index.js

@@ -24,12 +24,17 @@ var expectedZoneOverlaps = require('./expectedZoneOverlaps.json')
 
 const argv = yargs
   .option('downloads_dir', {
-    description: 'Set the download location',
+    description: 'Set the download location for features from OpenStreetMap',
     default: './downloads',
     type: 'string'
   })
+  .option('working_dir', {
+    description: 'Set the working files location for temporary / intermediate files',
+    default: './working',
+    type: 'string'
+  })
   .option('dist_dir', {
-    description: 'Set the dist location',
+    description: 'Set the dist location, for the generated release files',
     default: './dist',
     type: 'string'
   })
@@ -65,6 +70,7 @@ const argv = yargs
 // Resolve the arguments with paths so relative paths become absolute.
 const downloadsDir = path.resolve(argv.downloads_dir)
 const distDir = path.resolve(argv.dist_dir)
+const workingDir = path.resolve(argv.working_dir)
 
 // allow building of only a specified zones
 let includedZones = []
@@ -744,7 +750,7 @@ var downloadLastRelease = function (cb) {
         data = JSON.parse(data)
         // determine last release version name and download link
         const lastReleaseName = data.name
-        lastReleaseJSONfile = `./dist/${lastReleaseName}.json`
+        lastReleaseJSONfile = `${workingDir}/${lastReleaseName}.json`
         let lastReleaseDownloadUrl
         for (var i = 0; i < data.assets.length; i++) {
           if (data.assets[i].browser_download_url.indexOf('timezones-with-oceans.geojson') > -1) {
@@ -774,24 +780,18 @@ var downloadLastRelease = function (cb) {
               file.close((err) => {
                 if (err) return cb(err)
                 // unzip file
-                console.log('unzipping latest release')
+                console.log(`unzipping latest release from ${lastReleaseJSONfile}.zip`)
                 exec(
-                  `unzip -o ${lastReleaseJSONfile} -d dist`,
+                  `unzip -o ${lastReleaseJSONfile} -d ${workingDir}`,
                   err => {
                     if (err) { return cb(err) }
-                    console.log('unzipped file')
-                    console.log('moving unzipped file')
-                    // might need to change this after changes to how files are
-                    // zipped after 2020a
-                    fs.copyFile(
-                      path.join(
-                        'dist',
-                        'dist',
-                        'combined-with-oceans.json'
-                      ),
-                      lastReleaseJSONfile,
-                      cb
-                    )
+
+                    const srcFile = path.join(workingDir, 'combined-with-oceans.json')
+                    console.log(`unzipped file: ${srcFile}`)
+
+                    const destFile = lastReleaseJSONfile
+                    console.log(`Renaming ${srcFile} to ${destFile}`)
+                    fs.rename(srcFile, destFile, cb)
                   }
                 )
               })
@@ -892,11 +892,15 @@ var analyzeChangesFromLastRelease = function (cb) {
 
 const autoScript = {
   makeDownloadsDir: function (cb) {
-    overallProgress.beginTask('Creating downloads dir')
+    overallProgress.beginTask(`Creating downloads dir (${downloadsDir})`)
     safeMkdir(downloadsDir, cb)
   },
+  makeWorkingDir: function (cb) {
+    overallProgress.beginTask(`Creating working dir (${workingDir})`)
+    safeMkdir(workingDir, cb)
+  },
   makeDistDir: function (cb) {
-    overallProgress.beginTask('Creating dist dir')
+    overallProgress.beginTask(`Creating dist dir (${distDir})`)
     safeMkdir(distDir, cb)
   },
   getOsmBoundaries: ['makeDownloadsDir', function (results, cb) {
@@ -925,7 +929,7 @@ const autoScript = {
     exec('zip -j ' + distDir + '/input-data.zip ' + downloadsDir +
          '/* timezones.json osmBoundarySources.json expectedZoneOverlaps.json', cb)
   }],
-  downloadLastRelease: ['makeDistDir', function (results, cb) {
+  downloadLastRelease: ['makeWorkingDir', function (results, cb) {
     if (argv.skip_analyze_diffs) {
       overallProgress.beginTask('WARNING: Skipping download of last release for analysis!')
       cb()