Fix #603: add import/export provider to work with JSON fs images

tests/index.js

@@ -51,6 +51,7 @@ require('./spec/providers/providers.spec');
 require('./spec/providers/providers.indexeddb.spec');
 require('./spec/providers/providers.websql.spec');
 require('./spec/providers/providers.memory.spec');
+require('./spec/providers/import-export-provider.spec');
 
 // Filer.FileSystemShell.*
 require('./spec/shell/cd.spec');

tests/lib/import-export-provider.js

@@ -0,0 +1,36 @@
+const MemoryProvider = require('../../src/providers/memory');
+const { parseBJSON } = require('../lib/test-utils');
+
+class ImportExportProvider extends MemoryProvider {
+
+  constructor(name, jsonImage) {
+    super(name);
+    this.unparsedJSONImage = jsonImage;
+  }
+
+  /**
+   * In addition to the usual setup of a Memory provider,
+   * also parse and overwrite the internal database.
+   */
+  open(callback) {
+    super.open(err => {
+      if(err) {
+        return callback(err);
+      }
+
+      try {
+        this.db = parseBJSON(this.unparsedJSONImage);
+        this.unparsedJSONImage = null;
+        callback();
+      } catch(e) {
+        callback(new Error(`unable to parse JSON filesystem image: ${e.message}`));
+      }
+    });
+  }
+
+  export() {
+    return JSON.stringify(this.db);
+  }
+}
+
+module.exports = ImportExportProvider;

tests/lib/test-utils.js

@@ -140,6 +140,16 @@ function typedArrayEqual(a, b) {
   return true;
 }
 
+/**
+ * Parse JSON with serialized Buffers
+ */
+const parseBJSON = json =>
+  JSON.parse(json, (key, value) =>
+    value && value.type === 'Buffer' ?
+      Buffer.from(value.data) :
+      value
+  );
+
 module.exports = {
   uniqueName: uniqueName,
   setup: setup,
@@ -152,5 +162,6 @@ module.exports = {
     Memory: MemoryTestProvider
   },
   cleanup: cleanup,
-  typedArrayEqual: typedArrayEqual
+  typedArrayEqual: typedArrayEqual,
+  parseBJSON
 };

tests/spec/providers/import-export-provider.spec.js

@@ -0,0 +1,203 @@
+var { uniqueName, parseBJSON } = require('../../lib/test-utils.js');
+var ImportExportProvider = require('../../lib/import-export-provider');
+var expect = require('chai').expect;
+
+describe('Filer Provider Tests for ImportExportProvider', function() {
+  var provider;
+
+  /**
+   * Simulate the sort of data a filesystem image would have
+   */
+  var image = {
+    'c20b2b02-81f5-43af-b117-78bc0affd1b7': {
+      name: 'file',
+      size: 36,
+      mtime: Date.now()
+    },
+    '85ad404e-c29b-4c63-bb21-69655375d367': Buffer.from('data')
+  };
+  function buildImageJSON() {
+    return JSON.stringify(image);
+  }
+
+  beforeEach(function() {
+    provider = new ImportExportProvider(uniqueName(), buildImageJSON());
+  });
+
+  afterEach(function() {
+    provider = null;
+  });
+
+  it('has open, getReadOnlyContext, and getReadWriteContext instance methods', function() {
+    expect(provider.open).to.be.a('function');
+    expect(provider.getReadOnlyContext).to.be.a('function');
+    expect(provider.getReadWriteContext).to.be.a('function');
+  });
+
+  it('should open a new provider database', function(done) {
+    provider.open(function(error) {
+      expect(error).not.to.exist;
+      done();
+    });
+  });
+
+  it('should have expected Object type from imported image', function(done) {
+    provider.open(function(error) {
+      if (error) throw error;
+
+      var context = provider.getReadWriteContext();
+      context.getObject('c20b2b02-81f5-43af-b117-78bc0affd1b7', function(error, o) {
+        if (error) throw error;
+
+        expect(o).to.deep.equal(image['c20b2b02-81f5-43af-b117-78bc0affd1b7']);
+        done();
+      });
+    });
+  });
+
+  it('should have expected Buffer type from imported image', function(done) {
+    provider.open(function(error) {
+      if (error) throw error;
+
+      var context = provider.getReadWriteContext();
+      context.getObject('85ad404e-c29b-4c63-bb21-69655375d367', function(error, o) {
+        if (error) throw error;
+
+        expect(o).to.deep.equal(image['85ad404e-c29b-4c63-bb21-69655375d367']);
+        done();
+      });
+    });
+  });
+
+  it('should allow exporting the filesystem image', function(done) {
+    provider.open(function(error) {
+      if (error) throw error;
+
+      var bjson = provider.export();
+      var exported = parseBJSON(bjson);
+
+      expect(exported['c20b2b02-81f5-43af-b117-78bc0affd1b7']).to.deep.equal(image['c20b2b02-81f5-43af-b117-78bc0affd1b7']);
+      expect(exported['85ad404e-c29b-4c63-bb21-69655375d367']).to.deep.equal(image['85ad404e-c29b-4c63-bb21-69655375d367']);
+
+      done();
+    });
+  });
+
+  it('should allow putObject() and getObject()', function(done) {
+    provider.open(function(error) {
+      if (error) throw error;
+
+      var context = provider.getReadWriteContext();
+      // Simple JS Object
+      var value = {
+        a: 'a',
+        b: 1,
+        c: true,
+        d: [1, 2, 3],
+        e: {
+          e1: ['a', 'b', 'c']
+        }
+      };
+      context.putObject('key', value, function(error) {
+        if (error) throw error;
+
+        context.getObject('key', function(error, result) {
+          expect(error).not.to.exist;
+          expect(result).to.be.an('object');
+          expect(result).to.deep.equal(value);
+          done();
+        });
+      });
+    });
+  });
+
+  it('should allow putBuffer() and getBuffer()', function(done) {
+    provider.open(function(error) {
+      if (error) throw error;
+
+      var context = provider.getReadWriteContext();
+      var buf = Buffer.from([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
+      context.putBuffer('key', buf, function(error) {
+        if (error) throw error;
+
+        context.getBuffer('key', function(error, result) {
+          expect(error).not.to.exist;
+          expect(Buffer.isBuffer(result)).to.be.true;
+          expect(result).to.deep.equal(buf);
+          done();
+        });
+      });
+    });
+  });
+
+  it('should allow zero-length Buffers with putBuffer() and getBuffer()', function(done) {
+    provider.open(function(error) {
+      if (error) throw error;
+
+      var context = provider.getReadWriteContext();
+      // Zero-length Buffer
+      var buf = Buffer.alloc(0);
+      context.putBuffer('key', buf, function(error) {
+        if (error) throw error;
+
+        context.getBuffer('key', function(error, result) {
+          expect(error).not.to.exist;
+          expect(Buffer.isBuffer(result)).to.be.true;
+          expect(result).to.deep.equal(buf);
+          done();
+        });
+      });
+    });
+  });
+
+  it('should allow delete()', function(done) {
+    provider.open(function(error) {
+      if (error) throw error;
+
+      var context = provider.getReadWriteContext();
+      context.putObject('key', 'value', function(error) {
+        if (error) throw error;
+
+        context.delete('key', function(error) {
+          if (error) throw error;
+
+          context.getObject('key', function(error, result) {
+            expect(error).not.to.exist;
+            expect(result).not.to.exist;
+            done();
+          });
+        });
+      });
+    });
+  });
+
+  it('should allow clear()', function(done) {
+    provider.open(function(error) {
+      if (error) throw error;
+
+      var context = provider.getReadWriteContext();
+      context.putObject('key1', 'value1', function(error) {
+        if (error) throw error;
+
+        context.putObject('key2', 'value2', function(error) {
+          if (error) throw error;
+
+          context.clear(function(error) {
+            if (error) throw error;
+
+            context.getObject('key1', function(error, result) {
+              if (error) throw error;
+              expect(result).not.to.exist;
+
+              context.getObject('key2', function(error, result) {
+                if (error) throw error;
+                expect(result).not.to.exist;
+                done();
+              });
+            });
+          });
+        });
+      });
+    });
+  });
+});