github.com/joshdk/godel@v0.0.0-20170529232908-862138a45aee/apps/distgo/cmd/run/run.go (about)

     1  // Copyright 2016 Palantir Technologies, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package run
    16  
    17  import (
    18  	"fmt"
    19  	"go/ast"
    20  	"go/parser"
    21  	"go/token"
    22  	"io"
    23  	"io/ioutil"
    24  	"os"
    25  	"os/exec"
    26  	"path"
    27  	"strings"
    28  
    29  	"github.com/pkg/errors"
    30  
    31  	"github.com/palantir/godel/apps/distgo/params"
    32  )
    33  
    34  func DoRun(buildSpec params.ProductBuildSpec, runArgs []string, stdout, stderr io.Writer) error {
    35  	mainPkgDir := path.Join(buildSpec.ProjectDir, buildSpec.Build.MainPkg)
    36  	mainPkgFileNames, err := mainPkgFileNames(mainPkgDir)
    37  	if err != nil {
    38  		return errors.Wrapf(err, "failed to find main file")
    39  	}
    40  
    41  	cmd := exec.Command("go")
    42  	args := []string{cmd.Path, "run"}
    43  	for _, name := range mainPkgFileNames {
    44  		args = append(args, path.Join(buildSpec.ProjectDir, buildSpec.Build.MainPkg, name))
    45  	}
    46  	args = append(args, buildSpec.Run.Args...)
    47  	args = append(args, transformRunFlagArgs(runArgs)...)
    48  	cmd.Args = args
    49  
    50  	cmd.Stdout = stdout
    51  	cmd.Stderr = stderr
    52  	cmd.Stdin = os.Stdin
    53  
    54  	fmt.Fprintln(stdout, strings.Join(args, " "))
    55  	if err := cmd.Run(); err != nil {
    56  		return errors.Wrapf(err, "go run failed")
    57  	}
    58  	return nil
    59  }
    60  
    61  func transformRunFlagArgs(args []string) []string {
    62  	const flagPrefix = "flag:"
    63  	var newArgs []string
    64  	for _, currArg := range args {
    65  		// if current argument has flag prefix and has content after the prefix, trim the prefix
    66  		if strings.HasPrefix(currArg, flagPrefix) && len(currArg) > len(flagPrefix) {
    67  			currArg = strings.TrimPrefix(currArg, flagPrefix)
    68  		}
    69  		newArgs = append(newArgs, currArg)
    70  	}
    71  	return newArgs
    72  }
    73  
    74  // getMainPkgFiles returns the names of all of the files in the "main" pkg of the specified directory. Returns an error
    75  // if there are no files in the "main" package that declares a "main" function (or if there are multiple such files).
    76  func mainPkgFileNames(mainPkgDir string) ([]string, error) {
    77  	fileInfos, err := ioutil.ReadDir(mainPkgDir)
    78  	if err != nil {
    79  		return nil, errors.Wrapf(err, "failed to list files in directory %v", mainPkgDir)
    80  	}
    81  	var mainPkgFileNames []string
    82  	var mainFuncFileNames []string
    83  	for _, currFile := range fileInfos {
    84  		currFilePath := path.Join(mainPkgDir, currFile.Name())
    85  		if !currFile.IsDir() && strings.HasSuffix(currFile.Name(), ".go") && !strings.HasSuffix(currFile.Name(), "_test.go") {
    86  			fset := token.NewFileSet()
    87  			fnode, err := parser.ParseFile(fset, currFilePath, nil, parser.ParseComments)
    88  			if err != nil {
    89  				return nil, errors.Wrapf(err, "failed to parse file %v", currFilePath)
    90  			}
    91  
    92  			// find main package
    93  			if fnode.Name.Name == "main" {
    94  				mainPkgFileNames = append(mainPkgFileNames, currFile.Name())
    95  				if hasMainFunc(fnode) {
    96  					mainFuncFileNames = append(mainFuncFileNames, currFile.Name())
    97  				}
    98  			}
    99  		}
   100  	}
   101  
   102  	switch len(mainFuncFileNames) {
   103  	case 0:
   104  		return nil, errors.Errorf("no go file with main package and main function exists in directory %v", mainPkgDir)
   105  	case 1:
   106  		return mainPkgFileNames, nil
   107  	default:
   108  		return nil, errors.Errorf("directory %v contain multiple files that have main package and main function: %v", mainPkgDir, mainFuncFileNames)
   109  	}
   110  }
   111  
   112  func hasMainFunc(node *ast.File) bool {
   113  	for _, currDecl := range node.Decls {
   114  		switch t := currDecl.(type) {
   115  		case *ast.FuncDecl:
   116  			if t.Name.Name == "main" {
   117  				return true
   118  			}
   119  		}
   120  	}
   121  	return false
   122  }