New Mojom Parser: Serialization.

mojom/mojom_parser/serialization/serialization_test.go

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package serialization
+
+import (
+        "fmt"
+        "mojo/public/go/bindings"
+        "mojom/mojom_parser/generated/mojom_files"
+        "mojom/mojom_parser/generated/mojom_types"
+        "mojom/mojom_parser/mojom"
+        "mojom/mojom_parser/parser"
+        "reflect"
+        "testing"
+        myfmt "third_party/golang/src/fmt"
+)
+
+// TestSingleFileSerialization uses a series of test cases in which the text of a .mojom
+// file is specified and the expected MojomFileGraph is specified using Go struct literals.
+func TestSingleFileSerialization(t *testing.T) {
+
+        type testCase struct {
+                fileName             string
+                mojomContents        string
+                lineAndcolumnNumbers bool
+                expectedGraph        *mojom_files.MojomFileGraph
+        }
+        cases := make([]testCase, 0)
+        testCaseNum := 0
+        var expectedGraph *mojom_files.MojomFileGraph
+        var expectedFile *mojom_files.MojomFile
+        var fileName string
+
+        startTestCase := func(moduleNameSpace string) {

[mattr, 2015/11/10 19:26:49]

I found this structure a bit confusing.  You could also do:

func defineTestCase(moduleNamespace string, body func(*testCase)) {
  // do the stuff from startTestCase
  body(newTestCase)
  // do the stuff from endTestCase
}

then pass it a function roughly corresponding to the block you've defined for
the existing test case.

[rudominer, 2015/11/10 23:29:36]

I have refactored the test to try to make it more readable. I did not do exactly
as you suggested but I did
extract all of the local functions into real defined functions.

+                fileName = fmt.Sprintf("file%d", testCaseNum)
+                expectedGraph = new(mojom_files.MojomFileGraph)
+                expectedGraph.Files = make(map[string]mojom_files.MojomFile)
+                expectedFile = new(mojom_files.MojomFile)
+                expectedFile.FileName = fileName
+                expectedFile.ModuleNamespace = new(string)
+                *expectedFile.ModuleNamespace = moduleNameSpace
+                expectedGraph.ResolvedTypes = make(map[string]mojom_types.UserDefinedType)
+                expectedGraph.ResolvedValues = make(map[string]mojom_types.UserDefinedValue)
+                // We don't want to bother with line and column numbers which are brittle.
+                lineAndcolumnNumbers := false
+                cases = append(cases, testCase{fileName, "", lineAndcolumnNumbers, expectedGraph})
+        }
+
+        endTestCase := func() {
+                expectedGraph.Files[fileName] = *expectedFile
+                testCaseNum += 1
+        }
+
+        newDeclData := func(shortName, fullIdentifier string) *mojom_types.DeclarationData {
+                return &mojom_types.DeclarationData{
+                        ShortName:        newString(shortName),
+                        FullIdentifier:   newString(fullIdentifier),
+                        DeclaredOrdinal:  -1,
+                        DeclarationOrder: -1,
+                        SourceFileInfo: &mojom_types.SourceFileInfo{
+                                FileName: fileName,
+                        }}
+        }
+
+        ////////////////////////////////////////////////////////////
+        // Test Case
+        ////////////////////////////////////////////////////////////
+        startTestCase("mojom.test")
+        cases[testCaseNum].mojomContents = `
+        [go_namespace="go.test",
+        lucky=true,
+        planet=EARTH]
+        module mojom.test;
+
+        import "another.file";
+        import "and.another.file";
+
+        const uint16 NUM_MAGI = 3;
+
+        struct Foo{
+                int32 x;
+                string y = "hello";
+                string? z;
+
+                enum Hats {
+                        TOP,
+                        COWBOY = NUM_MAGI
+                };
+        };`
+        {
+                // Attributes
+                expectedFile.Attributes = &[]mojom_types.Attribute{
+                        {"go_namespace", "go.test"}, {"lucky", "true"}, {"planet", "EARTH"},
+                }
+
+                // Imports
+                expectedFile.Imports = &[]string{
+                        "another.file.canonical", "and.another.file.canonical",
+                }
+
+                // DeclaredMojomObjects
+                expectedFile.DeclaredMojomObjects.Structs = &[]string{"ooF.tset.mojom"}
+                expectedFile.DeclaredMojomObjects.TopLevelConstants = &[]string{"IGAM_MUN.tset.mojom"}
+
+                // Resolved Values
+
+                // NUM_MAGI
+                expectedGraph.ResolvedValues["IGAM_MUN.tset.mojom"] = &mojom_types.UserDefinedValueDeclaredConstant{mojom_types.DeclaredConstant{
+                        DeclData: *newDeclData("NUM_MAGI", "mojom.test.NUM_MAGI"),
+                        Type:     &mojom_types.TypeSimpleType{mojom_types.SimpleType_UinT16},
+                        Value:    &mojom_types.ValueLiteralValue{&mojom_types.LiteralValueInt64Value{3}},
+                }}
+
+                // Hats.TOP
+                expectedGraph.ResolvedValues["POT.staH.ooF.tset.mojom"] = &mojom_types.UserDefinedValueEnumValue{mojom_types.EnumValue{
+                        DeclData:    newDeclData("TOP", "mojom.test.Foo.Hats.TOP"),
+                        EnumTypeKey: "staH.ooF.tset.mojom",
+                        IntValue:    -1,
+                }}
+
+                // Hats.COWBOY
+                expectedGraph.ResolvedValues["YOBWOC.staH.ooF.tset.mojom"] = &mojom_types.UserDefinedValueEnumValue{mojom_types.EnumValue{
+                        DeclData:    newDeclData("COWBOY", "mojom.test.Foo.Hats.COWBOY"),
+                        EnumTypeKey: "staH.ooF.tset.mojom",
+                        IntValue:    3,
+                        InitializerValue: &mojom_types.ValueUserValueReference{mojom_types.UserValueReference{
+                                Identifier:            "NUM_MAGI",
+                                ValueKey:              newString("IGAM_MUN.tset.mojom"),
+                                ResolvedConcreteValue: &mojom_types.ValueLiteralValue{&mojom_types.LiteralValueInt64Value{3}},
+                        }},
+                }}
+
+                // ResolvedTypes
+
+                // struct Foo
+                expectedGraph.ResolvedTypes["ooF.tset.mojom"] = &mojom_types.UserDefinedTypeStructType{mojom_types.MojomStruct{
+                        DeclData: &mojom_types.DeclarationData{
+                                ShortName:        newString("Foo"),
+                                FullIdentifier:   newString("mojom.test.Foo"),
+                                DeclaredOrdinal:  -1,
+                                DeclarationOrder: -1,
+                                SourceFileInfo: &mojom_types.SourceFileInfo{
+                                        FileName: fileName,
+                                },
+                                ContainedDeclarations: &mojom_types.ContainedDeclarations{
+                                        Enums: &[]string{"staH.ooF.tset.mojom"}},
+                        },
+                        Fields: []mojom_types.StructField{
+                                // field x
+                                {
+                                        DeclData: newDeclData("x", ""),
+                                        Type:     &mojom_types.TypeSimpleType{mojom_types.SimpleType_InT32},
+                                },
+                                // field y
+                                {
+                                        DeclData:     newDeclData("y", ""),
+                                        Type:         &mojom_types.TypeStringType{mojom_types.StringType{false}},
+                                        DefaultValue: &mojom_types.DefaultFieldValueValue{&mojom_types.ValueLiteralValue{&mojom_types.LiteralValueStringValue{"hello"}}},
+                                },
+                                // field z
+                                {
+                                        DeclData: newDeclData("z", ""),
+                                        Type:     &mojom_types.TypeStringType{mojom_types.StringType{true}},
+                                },
+                        },
+                }}
+
+                // enum Hats
+                expectedGraph.ResolvedTypes["staH.ooF.tset.mojom"] = &mojom_types.UserDefinedTypeEnumType{mojom_types.MojomEnum{
+                        DeclData: newDeclData("Hats", "mojom.test.Foo.Hats"),
+                        Values: []mojom_types.EnumValue{
+                                // Note(rudominer) It is a bug that we need to copy the enum values here.
+                                // See https://github.com/domokit/mojo/issues/513.
+                                // value TOP
+                                expectedGraph.ResolvedValues["POT.staH.ooF.tset.mojom"].(*mojom_types.UserDefinedValueEnumValue).Value,
+                                // value COWBOY
+                                expectedGraph.ResolvedValues["YOBWOC.staH.ooF.tset.mojom"].(*mojom_types.UserDefinedValueEnumValue).Value,
+                        },
+                }}
+        }
+
+        endTestCase()
+
+        ////////////////////////////////////////////////////////////
+        // Execute all of the test cases.
+        ////////////////////////////////////////////////////////////
+        for _, c := range cases {
+                // Parse and resolve the mojom input.
+                descriptor := mojom.NewMojomDescriptor()
+                parser := parser.MakeParser(c.fileName, c.mojomContents, descriptor)
+                parser.Parse()
+                if !parser.OK() {
+                        t.Errorf("Parsing error for %s: %s", c.fileName, parser.GetError().Error())
+                        continue
+                }
+                if err := descriptor.Resolve(); err != nil {
+                        t.Errorf("Resolve error for %s: %s", c.fileName, err.Error())
+                        continue
+                }
+                if err := descriptor.ComputeEnumValueIntegers(); err != nil {
+                        t.Errorf("ComputeEnumValueIntegers error for %s: %s", c.fileName, err.Error())
+                        continue
+                }
+                if err := descriptor.ComputeDataForGenerators(); err != nil {
+                        t.Errorf("ComputeDataForGenerators error for %s: %s", c.fileName, err.Error())
+                        continue
+                }
+
+                // Simulate setting the canonical file name for the imported files. In real operation
+                // this step is done in parser_driver.go when each of the imported files are parsed.
+                mojomFile := parser.GetMojomFile()
+                if mojomFile.Imports != nil {
+                        for _, imp := range mojomFile.Imports {
+                                imp.CanonicalFileName = fmt.Sprintf("%s.canonical", imp.SpecifiedName)
+                        }
+                }
+
+                // Serialize
+                EmitLineAndColumnNumbers = c.lineAndcolumnNumbers
+                bytes, err := Serialize(descriptor)
+                if err != nil {
+                        t.Errorf("Serialization error for %s: %s", c.fileName, err.Error())
+                        continue
+                }
+
+                // Deserialize
+                decoder := bindings.NewDecoder(bytes, nil)
+                fileGraph := mojom_files.MojomFileGraph{}
+                fileGraph.Decode(decoder)
+
+                // Compare
+                if err := compareFileGraphs(c.expectedGraph, &fileGraph); err != nil {
+                        t.Errorf("%s:\n%s", c.fileName, err.Error())
+                        continue
+                }
+        }
+}
+
+// compareFileGraphs compares |expected| and |actual| and returns a non-nil
+// error if they are not deeply equal. The error message contains a human-readable
+// string containing a deep-print of expected and actual along with the substrings
+// starting from the first character where they differ.
+func compareFileGraphs(expected *mojom_files.MojomFileGraph, actual *mojom_files.MojomFileGraph) error {
+        if !reflect.DeepEqual(expected, actual) {
+                // Note(rudominer) The myfmt package is a local modification of the fmt package
+                // that does a deep printing that follows pointers for up to 50 levels.
+                // Thus expectedString and actualString should contain enough information to
+                // precisely capture the structure of expected and actual.
+                expectedString := myfmt.Sprintf("%+v", expected)
+                actualString := myfmt.Sprintf("%+v", actual)
+                if expectedString != actualString {
+                        diffPos := -1
+                        for i := 0; i < len(expectedString) && i < len(actualString); i++ {
+                                if expectedString[i] != actualString[i] {
+                                        diffPos = i
+                                        break
+                                }
+                        }
+                        mismatchExpected := ""
+                        mismatchActual := ""
+                        if diffPos > -1 {
+                                mismatchExpected = expectedString[diffPos:]
+                                mismatchActual = actualString[diffPos:]
+                        }
+                        return fmt.Errorf("*****\nexpected=\n*****\n%q\n*****\nactual=\n*****\n%q\n*****\n"+
+                                "match failed at position %d: expected=\n*****\n%s\n******\nactual=\n*****\n%s\n******\n",
+                                expectedString, actualString, diffPos, mismatchExpected, mismatchActual)
+                } else {
+                        return fmt.Errorf("expected != actual but the two printed equal.")
+                }
+        }
+        return nil
+}