github.com/powerman/golang-tools@v0.1.11-0.20220410185822-5ad214d8d803/internal/apidiff/report.go (about)

     1  // Copyright 2019 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package apidiff
     6  
     7  import (
     8  	"bytes"
     9  	"fmt"
    10  	"io"
    11  )
    12  
    13  // Report describes the changes detected by Changes.
    14  type Report struct {
    15  	Changes []Change
    16  }
    17  
    18  // A Change describes a single API change.
    19  type Change struct {
    20  	Message    string
    21  	Compatible bool
    22  }
    23  
    24  func (r Report) messages(compatible bool) []string {
    25  	var msgs []string
    26  	for _, c := range r.Changes {
    27  		if c.Compatible == compatible {
    28  			msgs = append(msgs, c.Message)
    29  		}
    30  	}
    31  	return msgs
    32  }
    33  
    34  func (r Report) String() string {
    35  	var buf bytes.Buffer
    36  	if err := r.Text(&buf); err != nil {
    37  		return fmt.Sprintf("!!%v", err)
    38  	}
    39  	return buf.String()
    40  }
    41  
    42  func (r Report) Text(w io.Writer) error {
    43  	if err := r.TextIncompatible(w, true); err != nil {
    44  		return err
    45  	}
    46  	return r.TextCompatible(w)
    47  }
    48  
    49  func (r Report) TextIncompatible(w io.Writer, withHeader bool) error {
    50  	if withHeader {
    51  		return r.writeMessages(w, "Incompatible changes:", r.messages(false))
    52  	}
    53  	return r.writeMessages(w, "", r.messages(false))
    54  }
    55  
    56  func (r Report) TextCompatible(w io.Writer) error {
    57  	return r.writeMessages(w, "Compatible changes:", r.messages(true))
    58  }
    59  
    60  func (r Report) writeMessages(w io.Writer, header string, msgs []string) error {
    61  	if len(msgs) == 0 {
    62  		return nil
    63  	}
    64  	if header != "" {
    65  		if _, err := fmt.Fprintf(w, "%s\n", header); err != nil {
    66  			return err
    67  		}
    68  	}
    69  	for _, m := range msgs {
    70  		if _, err := fmt.Fprintf(w, "- %s\n", m); err != nil {
    71  			return err
    72  		}
    73  	}
    74  	return nil
    75  }