main.go

Documentation: cmd/cover/testdata

     1  // Copyright 2013 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  // Test runner for coverage test. This file is not coverage-annotated; test.go is.
     6  // It knows the coverage counter is called
     7  // "thisNameMustBeVeryLongToCauseOverflowOfCounterIncrementStatementOntoNextLineForTest".
     8  
     9  package main
    10  
    11  import (
    12  	"fmt"
    13  	"os"
    14  )
    15  
    16  func main() {
    17  	testAll()
    18  	verify()
    19  }
    20  
    21  type block struct {
    22  	count uint32
    23  	line  uint32
    24  }
    25  
    26  var counters = make(map[block]bool)
    27  
    28  // shorthand for the long counter variable.
    29  var coverTest = &thisNameMustBeVeryLongToCauseOverflowOfCounterIncrementStatementOntoNextLineForTest
    30  
    31  // check records the location and expected value for a counter.
    32  func check(line, count uint32) {
    33  	b := block{
    34  		count,
    35  		line,
    36  	}
    37  	counters[b] = true
    38  }
    39  
    40  // checkVal is a version of check that returns its extra argument,
    41  // so it can be used in conditionals.
    42  func checkVal(line, count uint32, val int) int {
    43  	b := block{
    44  		count,
    45  		line,
    46  	}
    47  	counters[b] = true
    48  	return val
    49  }
    50  
    51  var PASS = true
    52  
    53  // verify checks the expected counts against the actual. It runs after the test has completed.
    54  func verify() {
    55  	for b := range counters {
    56  		got, index := count(b.line)
    57  		if b.count == anything && got != 0 {
    58  			got = anything
    59  		}
    60  		if got != b.count {
    61  			fmt.Fprintf(os.Stderr, "test_go:%d expected count %d got %d [counter %d]\n", b.line, b.count, got, index)
    62  			PASS = false
    63  		}
    64  	}
    65  	verifyPanic()
    66  	if !PASS {
    67  		fmt.Fprintf(os.Stderr, "FAIL\n")
    68  		os.Exit(2)
    69  	}
    70  }
    71  
    72  // verifyPanic is a special check for the known counter that should be
    73  // after the panic call in testPanic.
    74  func verifyPanic() {
    75  	if coverTest.Count[panicIndex-1] != 1 {
    76  		// Sanity check for test before panic.
    77  		fmt.Fprintf(os.Stderr, "bad before panic")
    78  		PASS = false
    79  	}
    80  	if coverTest.Count[panicIndex] != 0 {
    81  		fmt.Fprintf(os.Stderr, "bad at panic: %d should be 0\n", coverTest.Count[panicIndex])
    82  		PASS = false
    83  	}
    84  	if coverTest.Count[panicIndex+1] != 1 {
    85  		fmt.Fprintf(os.Stderr, "bad after panic")
    86  		PASS = false
    87  	}
    88  }
    89  
    90  // count returns the count and index for the counter at the specified line.
    91  func count(line uint32) (uint32, int) {
    92  	// Linear search is fine. Choose perfect fit over approximate.
    93  	// We can have a closing brace for a range on the same line as a condition for an "else if"
    94  	// and we don't want that brace to steal the count for the condition on the "if".
    95  	// Therefore we test for a perfect (lo==line && hi==line) match, but if we can't
    96  	// find that we take the first imperfect match.
    97  	index := -1
    98  	indexLo := uint32(1e9)
    99  	for i := range coverTest.Count {
   100  		lo, hi := coverTest.Pos[3*i], coverTest.Pos[3*i+1]
   101  		if lo == line && line == hi {
   102  			return coverTest.Count[i], i
   103  		}
   104  		// Choose the earliest match (the counters are in unpredictable order).
   105  		if lo <= line && line <= hi && indexLo > lo {
   106  			index = i
   107  			indexLo = lo
   108  		}
   109  	}
   110  	if index == -1 {
   111  		fmt.Fprintln(os.Stderr, "cover_test: no counter for line", line)
   112  		PASS = false
   113  		return 0, 0
   114  	}
   115  	return coverTest.Count[index], index
   116  }
   117
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