text: // Copyright 2014 The Go Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style
  // license that can be found in the LICENSE file.
  
  // This file contains tests for the bool checker.
  
  package a
  
  import "io"
  
  type T int
  
  func (t T) Foo() int { return int(t) }
  
  type FT func() int
  
  var S []int
  
  func RatherStupidConditions() {
  	var f, g func() int
  	if f() == 0 || f() == 0 { // OK f might have side effects
  	}
  	var t T
  	_ = t.Foo() == 2 || t.Foo() == 2        // OK Foo might have side effects
  	if v, w := f(), g(); v == w || v == w { // want `redundant or: v == w \|\| v == w`
  	}
  	_ = f == nil || f == nil // want `redundant or: f == nil \|\| f == nil`
  
  	var B byte
  	_ = B == byte(1) || B == byte(1) // want `redundant or: B == byte\(1\) \|\| B == byte\(1\)`
  	_ = t == T(2) || t == T(2)       // want `redundant or: t == T\(2\) \|\| t == T\(2\)`
  	_ = FT(f) == nil || FT(f) == nil // want `redundant or: FT\(f\) == nil \|\| FT\(f\) == nil`
  
  	_ = (func() int)(f) == nil || (func() int)(f) == nil // want `redundant or: \(func\(\) int\)\(f\) == nil \|\| \(func\(\) int\)\(f\) == nil`
  	_ = append(S, 3) == nil || append(S, 3) == nil       // OK append has side effects
  
  	var namedFuncVar FT
  	_ = namedFuncVar() == namedFuncVar() // OK still func calls
  
  	var c chan int
  	_ = 0 == <-c || 0 == <-c                                  // OK subsequent receives may yield different values
  	for i, j := <-c, <-c; i == j || i == j; i, j = <-c, <-c { // want `redundant or: i == j \|\| i == j`
  	}
  
  	var i, j, k int
  	_ = i+1 == 1 || i+1 == 1         // want `redundant or: i\+1 == 1 \|\| i\+1 == 1`
  	_ = i == 1 || j+1 == i || i == 1 // want `redundant or: i == 1 \|\| i == 1`
  
  	// The various r.* patterns are intended to match duplicate
  	// diagnostics reported for the same underlying problem.
  	// See github.com/golang/go/issues/28086.
  	// TODO(adonovan): fix the checker.
  
  	_ = i == 1 || i == 1 || f() == 1 // want `redundant or: i == 1 \|\| i == 1` `r.*`
  	_ = i == 1 || f() == 1 || i == 1 // OK f may alter i as a side effect
  	_ = f() == 1 || i == 1 || i == 1 // want `redundant or: i == 1 \|\| i == 1`
  
  	// Test partition edge cases
  	_ = f() == 1 || i == 1 || i == 1 || j == 1 // want `redundant or: i == 1 \|\| i == 1` `r.*`
  	_ = f() == 1 || j == 1 || i == 1 || i == 1 // want `redundant or: i == 1 \|\| i == 1`
  	_ = i == 1 || f() == 1 || i == 1 || i == 1 // want `redundant or: i == 1 \|\| i == 1`
  	_ = i == 1 || i == 1 || f() == 1 || i == 1 // want `redundant or: i == 1 \|\| i == 1` `r.*` `r.*`
  	_ = i == 1 || i == 1 || j == 1 || f() == 1 // want `redundant or: i == 1 \|\| i == 1` `r.*` `r.*`
  	_ = j == 1 || i == 1 || i == 1 || f() == 1 // want `redundant or: i == 1 \|\| i == 1` `r.*`
  	_ = i == 1 || f() == 1 || f() == 1 || i == 1
  
  	_ = i == 1 || (i == 1 || i == 2)             // want `redundant or: i == 1 \|\| i == 1`
  	_ = i == 1 || (f() == 1 || i == 1)           // OK f may alter i as a side effect
  	_ = i == 1 || (i == 1 || f() == 1)           // want `redundant or: i == 1 \|\| i == 1`
  	_ = i == 1 || (i == 2 || (i == 1 || i == 3)) // want `redundant or: i == 1 \|\| i == 1`
  
  	var a, b bool
  	_ = i == 1 || (a || (i == 1 || b)) // want `redundant or: i == 1 \|\| i == 1`
  
  	// Check that all redundant ors are flagged
  	_ = j == 0 ||
  		i == 1 ||
  		f() == 1 ||
  		j == 0 || // want `redundant or: j == 0 \|\| j == 0` `r.*`
  		i == 1 || // want `redundant or: i == 1 \|\| i == 1` `r.*` `r.*` `r.*`
  		i == 1 || // want `redundant or: i == 1 \|\| i == 1` `r.*` `r.*`
  		i == 1 ||
  		j == 0 ||
  		k == 0
  
  	_ = i == 1*2*3 || i == 1*2*3 // want `redundant or: i == 1\*2\*3 \|\| i == 1\*2\*3`
  
  	// These test that redundant, suspect expressions do not trigger multiple errors.
  	_ = i != 0 || i != 0 // want `redundant or: i != 0 \|\| i != 0`
  	_ = i == 0 && i == 0 // want `redundant and: i == 0 && i == 0`
  
  	// and is dual to or; check the basics and
  	// let the or tests pull the rest of the weight.
  	_ = 0 != <-c && 0 != <-c         // OK subsequent receives may yield different values
  	_ = f() != 0 && f() != 0         // OK f might have side effects
  	_ = f != nil && f != nil         // want `redundant and: f != nil && f != nil`
  	_ = i != 1 && i != 1 && f() != 1 // want `redundant and: i != 1 && i != 1` `r.*`
  	_ = i != 1 && f() != 1 && i != 1 // OK f may alter i as a side effect
  	_ = f() != 1 && i != 1 && i != 1 // want `redundant and: i != 1 && i != 1`
  }
  
  func RoyallySuspectConditions() {
  	var i, j int
  
  	_ = i == 0 || i == 1 // OK
  	_ = i != 0 || i != 1 // want `suspect or: i != 0 \|\| i != 1`
  	_ = i != 0 || 1 != i // want `suspect or: i != 0 \|\| 1 != i`
  	_ = 0 != i || 1 != i // want `suspect or: 0 != i \|\| 1 != i`
  	_ = 0 != i || i != 1 // want `suspect or: 0 != i \|\| i != 1`
  
  	_ = (0 != i) || i != 1 // want `suspect or: 0 != i \|\| i != 1`
  
  	_ = i+3 != 7 || j+5 == 0 || i+3 != 9 // want `suspect or: i\+3 != 7 \|\| i\+3 != 9`
  
  	_ = i != 0 || j == 0 || i != 1 // want `suspect or: i != 0 \|\| i != 1`
  
  	_ = i != 0 || i != 1<<4 // want `suspect or: i != 0 \|\| i != 1<<4`
  
  	_ = i != 0 || j != 0
  	_ = 0 != i || 0 != j
  
  	var s string
  	_ = s != "one" || s != "the other" // want `suspect or: s != .one. \|\| s != .the other.`
  
  	_ = "et" != "alii" || "et" != "cetera"         // want `suspect or: .et. != .alii. \|\| .et. != .cetera.`
  	_ = "me gustas" != "tu" || "le gustas" != "tu" // OK we could catch this case, but it's not worth the code
  
  	var err error
  	_ = err != nil || err != io.EOF // TODO catch this case?
  
  	// Sanity check and.
  	_ = i != 0 && i != 1 // OK
  	_ = i == 0 && i == 1 // want `suspect and: i == 0 && i == 1`
  	_ = i == 0 && 1 == i // want `suspect and: i == 0 && 1 == i`
  	_ = 0 == i && 1 == i // want `suspect and: 0 == i && 1 == i`
  	_ = 0 == i && i == 1 // want `suspect and: 0 == i && i == 1`
  }
  