short_test.go

     1  // Copyright 2009 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  // This file contains test cases for short valid and invalid programs.
     6  
     7  package parser
     8  
     9  import (
    10  	"go/internal/typeparams"
    11  	"testing"
    12  )
    13  
    14  var valids = []string{
    15  	"package p\n",
    16  	`package p;`,
    17  	`package p; import "fmt"; func f() { fmt.Println("Hello, World!") };`,
    18  	`package p; func f() { if f(T{}) {} };`,
    19  	`package p; func f() { _ = <-chan int(nil) };`,
    20  	`package p; func f() { _ = (<-chan int)(nil) };`,
    21  	`package p; func f() { _ = (<-chan <-chan int)(nil) };`,
    22  	`package p; func f() { _ = <-chan <-chan <-chan <-chan <-int(nil) };`,
    23  	`package p; func f(func() func() func());`,
    24  	`package p; func f(...T);`,
    25  	`package p; func f(float, ...int);`,
    26  	`package p; func f(x int, a ...int) { f(0, a...); f(1, a...,) };`,
    27  	`package p; func f(int,) {};`,
    28  	`package p; func f(...int,) {};`,
    29  	`package p; func f(x ...int,) {};`,
    30  	`package p; type T []int; var a []bool; func f() { if a[T{42}[0]] {} };`,
    31  	`package p; type T []int; func g(int) bool { return true }; func f() { if g(T{42}[0]) {} };`,
    32  	`package p; type T []int; func f() { for _ = range []int{T{42}[0]} {} };`,
    33  	`package p; var a = T{{1, 2}, {3, 4}}`,
    34  	`package p; func f() { select { case <- c: case c <- d: case c <- <- d: case <-c <- d: } };`,
    35  	`package p; func f() { select { case x := (<-c): } };`,
    36  	`package p; func f() { if ; true {} };`,
    37  	`package p; func f() { switch ; {} };`,
    38  	`package p; func f() { for _ = range "foo" + "bar" {} };`,
    39  	`package p; func f() { var s []int; g(s[:], s[i:], s[:j], s[i:j], s[i:j:k], s[:j:k]) };`,
    40  	`package p; var ( _ = (struct {*T}).m; _ = (interface {T}).m )`,
    41  	`package p; func ((T),) m() {}`,
    42  	`package p; func ((*T),) m() {}`,
    43  	`package p; func (*(T),) m() {}`,
    44  	`package p; func _(x []int) { for range x {} }`,
    45  	`package p; func _() { if [T{}.n]int{} {} }`,
    46  	`package p; func _() { map[int]int{}[0]++; map[int]int{}[0] += 1 }`,
    47  	`package p; func _(x interface{f()}) { interface{f()}(x).f() }`,
    48  	`package p; func _(x chan int) { chan int(x) <- 0 }`,
    49  	`package p; const (x = 0; y; z)`, // issue 9639
    50  	`package p; var _ = map[P]int{P{}:0, {}:1}`,
    51  	`package p; var _ = map[*P]int{&P{}:0, {}:1}`,
    52  	`package p; type T = int`,
    53  	`package p; type (T = p.T; _ = struct{}; x = *T)`,
    54  	`package p; type T (*int)`,
    55  	`package p; type _ struct{ ((int)) }`,
    56  	`package p; type _ struct{ (*(int)) }`,
    57  	`package p; type _ struct{ ([]byte) }`, // disallowed by type-checker
    58  	`package p; var _ = func()T(nil)`,
    59  	`package p; func _(T (P))`,
    60  	`package p; func _(T []E)`,
    61  	`package p; func _(T [P]E)`,
    62  	`package p; type _ [A+B]struct{}`,
    63  	`package p; func (R) _()`,
    64  	`package p; type _ struct{ f [n]E }`,
    65  	`package p; type _ struct{ f [a+b+c+d]E }`,
    66  	`package p; type I1 interface{}; type I2 interface{ I1 }`,
    67  }
    68  
    69  // validWithTParamsOnly holds source code examples that are valid if
    70  // parseTypeParams is set, but invalid if not. When checking with the
    71  // parseTypeParams set, errors are ignored.
    72  var validWithTParamsOnly = []string{
    73  	`package p; type _ []T[ /* ERROR "expected ';', found '\['" */ int]`,
    74  	`package p; type T[P any /* ERROR "expected ']', found any" */ ] struct { P }`,
    75  	`package p; type T[P comparable /* ERROR "expected ']', found comparable" */ ] struct { P }`,
    76  	`package p; type T[P comparable /* ERROR "expected ']', found comparable" */ [P]] struct { P }`,
    77  	`package p; type T[P1, /* ERROR "unexpected comma" */ P2 any] struct { P1; f []P2 }`,
    78  	`package p; func _[ /* ERROR "expected '\(', found '\['" */ T any]()()`,
    79  	`package p; func _(T (P))`,
    80  	`package p; func f[ /* ERROR "expected '\(', found '\['" */ A, B any](); func _() { _ = f[int, int] }`,
    81  	`package p; func _(x /* ERROR "mixed named and unnamed parameters" */ T[P1, P2, P3])`,
    82  	`package p; func _(x /* ERROR "mixed named and unnamed parameters" */ p.T[Q])`,
    83  	`package p; func _(p.T[ /* ERROR "missing ',' in parameter list" */ Q])`,
    84  	`package p; type _[A interface /* ERROR "expected ']', found 'interface'" */ {},] struct{}`,
    85  	`package p; type _[A interface /* ERROR "expected ']', found 'interface'" */ {}] struct{}`,
    86  	`package p; type _[A, /* ERROR "unexpected comma" */  B any,] struct{}`,
    87  	`package p; type _[A, /* ERROR "unexpected comma" */ B any] struct{}`,
    88  	`package p; type _[A any /* ERROR "expected ']', found any" */,] struct{}`,
    89  	`package p; type _[A any /* ERROR "expected ']', found any" */ ]struct{}`,
    90  	`package p; type _[A any /* ERROR "expected ']', found any" */ ] struct{ A }`,
    91  	`package p; func _[ /* ERROR "expected '\(', found '\['" */ T any]()`,
    92  	`package p; func _[ /* ERROR "expected '\(', found '\['" */ T any](x T)`,
    93  	`package p; func _[ /* ERROR "expected '\(', found '\['" */ T1, T2 any](x T)`,
    94  	`package p; func _[ /* ERROR "expected '\(', found '\['" */ A, B any](a A) B`,
    95  	`package p; func _[ /* ERROR "expected '\(', found '\['" */ A, B C](a A) B`,
    96  	`package p; func _[ /* ERROR "expected '\(', found '\['" */ A, B C[A, B]](a A) B`,
    97  
    98  	`package p; type _[A, /* ERROR "unexpected comma" */ B any] interface { _(a A) B }`,
    99  	`package p; type _[A, /* ERROR "unexpected comma" */ B C[A, B]] interface { _(a A) B }`,
   100  	`package p; func _[ /* ERROR "expected '\(', found '\['" */ T1, T2 interface{}](x T1) T2`,
   101  	`package p; func _[ /* ERROR "expected '\(', found '\['" */ T1 interface{ m() }, T2, T3 interface{}](x T1, y T3) T2`,
   102  	`package p; var _ = [ /* ERROR "expected expression" */ ]T[int]{}`,
   103  	`package p; var _ = [ /* ERROR "expected expression" */ 10]T[int]{}`,
   104  	`package p; var _ = func /* ERROR "expected expression" */ ()T[int]{}`,
   105  	`package p; var _ = map /* ERROR "expected expression" */ [T[int]]T[int]{}`,
   106  	`package p; var _ = chan /* ERROR "expected expression" */ T[int](x)`,
   107  	`package p; func _(_ T[ /* ERROR "missing ',' in parameter list" */ P], T P) T[P]`,
   108  	`package p; var _ T[ /* ERROR "expected ';', found '\['" */ chan int]`,
   109  
   110  	// TODO(rfindley) this error message could be improved.
   111  	`package p; func (_ /* ERROR "mixed named and unnamed parameters" */ R[P]) _(x T)`,
   112  	`package p; func (_ /* ERROR "mixed named and unnamed parameters" */ R[ P, Q]) _(x T)`,
   113  
   114  	`package p; func (R[P] /* ERROR "missing element type" */ ) _()`,
   115  	`package p; func _(T[P] /* ERROR "missing element type" */ )`,
   116  	`package p; func _(T[P1, /* ERROR "expected ']', found ','" */ P2, P3 ])`,
   117  	`package p; func _(T[P] /* ERROR "missing element type" */ ) T[P]`,
   118  	`package p; type _ struct{ T[P] /* ERROR "missing element type" */ }`,
   119  	`package p; type _ struct{ T[struct /* ERROR "expected expression" */ {a, b, c int}] }`,
   120  	`package p; type _ interface{int| /* ERROR "expected ';'" */ float32; bool; m(); string;}`,
   121  	`package p; type I1[T any /* ERROR "expected ']', found any" */ ] interface{}; type I2 interface{ I1[int] }`,
   122  	`package p; type I1[T any /* ERROR "expected ']', found any" */ ] interface{}; type I2[T any] interface{ I1[T] }`,
   123  	`package p; type _ interface { N[ /* ERROR "expected ';', found '\['" */ T] }`,
   124  	`package p; type T[P any /* ERROR "expected ']'" */ ] = T0`,
   125  }
   126  
   127  func TestValid(t *testing.T) {
   128  	t.Run("no tparams", func(t *testing.T) {
   129  		for _, src := range valids {
   130  			checkErrors(t, src, src, DeclarationErrors|AllErrors, false)
   131  		}
   132  	})
   133  	t.Run("tparams", func(t *testing.T) {
   134  		for _, src := range valids {
   135  			checkErrors(t, src, src, DeclarationErrors|AllErrors, false)
   136  		}
   137  		for _, src := range validWithTParamsOnly {
   138  			checkErrors(t, src, src, DeclarationErrors|AllErrors, false)
   139  		}
   140  	})
   141  }
   142  
   143  // TestSingle is useful to track down a problem with a single short test program.
   144  func TestSingle(t *testing.T) {
   145  	const src = `package p; var _ = T{}`
   146  	checkErrors(t, src, src, DeclarationErrors|AllErrors, true)
   147  }
   148  
   149  var invalids = []string{
   150  	`foo /* ERROR "expected 'package'" */ !`,
   151  	`package p; func f() { if { /* ERROR "missing condition" */ } };`,
   152  	`package p; func f() { if ; /* ERROR "missing condition" */ {} };`,
   153  	`package p; func f() { if f(); /* ERROR "missing condition" */ {} };`,
   154  	`package p; func f() { if _ = range /* ERROR "expected operand" */ x; true {} };`,
   155  	`package p; func f() { switch _ /* ERROR "expected switch expression" */ = range x; true {} };`,
   156  	`package p; func f() { for _ = range x ; /* ERROR "expected '{'" */ ; {} };`,
   157  	`package p; func f() { for ; ; _ = range /* ERROR "expected operand" */ x {} };`,
   158  	`package p; func f() { for ; _ /* ERROR "expected boolean or range expression" */ = range x ; {} };`,
   159  	`package p; func f() { switch t = /* ERROR "expected ':=', found '='" */ t.(type) {} };`,
   160  	`package p; func f() { switch t /* ERROR "expected switch expression" */ , t = t.(type) {} };`,
   161  	`package p; func f() { switch t /* ERROR "expected switch expression" */ = t.(type), t {} };`,
   162  	`package p; var a = [ /* ERROR "expected expression" */ 1]int;`,
   163  	`package p; var a = [ /* ERROR "expected expression" */ ...]int;`,
   164  	`package p; var a = struct /* ERROR "expected expression" */ {}`,
   165  	`package p; var a = func /* ERROR "expected expression" */ ();`,
   166  	`package p; var a = interface /* ERROR "expected expression" */ {}`,
   167  	`package p; var a = [ /* ERROR "expected expression" */ ]int`,
   168  	`package p; var a = map /* ERROR "expected expression" */ [int]int`,
   169  	`package p; var a = chan /* ERROR "expected expression" */ int;`,
   170  	`package p; var a = []int{[ /* ERROR "expected expression" */ ]int};`,
   171  	`package p; var a = ( /* ERROR "expected expression" */ []int);`,
   172  	`package p; var a = <- /* ERROR "expected expression" */ chan int;`,
   173  	`package p; func f() { select { case _ <- chan /* ERROR "expected expression" */ int: } };`,
   174  	`package p; func f() { _ = (<-<- /* ERROR "expected 'chan'" */ chan int)(nil) };`,
   175  	`package p; func f() { _ = (<-chan<-chan<-chan<-chan<-chan<- /* ERROR "expected channel type" */ int)(nil) };`,
   176  	`package p; func f() { var t []int; t /* ERROR "expected identifier on left side of :=" */ [0] := 0 };`,
   177  	`package p; func f() { if x := g(); x /* ERROR "expected boolean expression" */ = 0 {}};`,
   178  	`package p; func f() { _ = x = /* ERROR "expected '=='" */ 0 {}};`,
   179  	`package p; func f() { _ = 1 == func()int { var x bool; x = x = /* ERROR "expected '=='" */ true; return x }() };`,
   180  	`package p; func f() { var s []int; _ = s[] /* ERROR "expected operand" */ };`,
   181  	`package p; func f() { var s []int; _ = s[i:j: /* ERROR "3rd index required" */ ] };`,
   182  	`package p; func f() { var s []int; _ = s[i: /* ERROR "2nd index required" */ :k] };`,
   183  	`package p; func f() { var s []int; _ = s[i: /* ERROR "2nd index required" */ :] };`,
   184  	`package p; func f() { var s []int; _ = s[: /* ERROR "2nd index required" */ :] };`,
   185  	`package p; func f() { var s []int; _ = s[: /* ERROR "2nd index required" */ ::] };`,
   186  	`package p; func f() { var s []int; _ = s[i:j:k: /* ERROR "expected ']'" */ l] };`,
   187  	`package p; func f() { for x /* ERROR "boolean or range expression" */ = []string {} }`,
   188  	`package p; func f() { for x /* ERROR "boolean or range expression" */ := []string {} }`,
   189  	`package p; func f() { for i /* ERROR "boolean or range expression" */ , x = []string {} }`,
   190  	`package p; func f() { for i /* ERROR "boolean or range expression" */ , x := []string {} }`,
   191  	`package p; func f() { go f /* ERROR HERE "function must be invoked" */ }`,
   192  	`package p; func f() { defer func() {} /* ERROR HERE "function must be invoked" */ }`,
   193  	`package p; func f() { go func() { func() { f(x func /* ERROR "missing ','" */ (){}) } } }`,
   194  	`package p; func _() (type /* ERROR "found 'type'" */ T)(T)`,
   195  	`package p; func (type /* ERROR "found 'type'" */ T)(T) _()`,
   196  	`package p; type _[A+B, /* ERROR "unexpected comma" */ ] int`,
   197  
   198  	// TODO(rfindley): this error should be positioned on the ':'
   199  	`package p; var a = a[[]int:[ /* ERROR "expected expression" */ ]int];`,
   200  
   201  	// TODO(rfindley): the compiler error is better here: "cannot parenthesize embedded type"
   202  	// TODO(rfindley): confirm that parenthesized types should now be accepted.
   203  	// `package p; type I1 interface{}; type I2 interface{ (/* ERROR "expected '}', found '\('" */ I1) }`,
   204  
   205  	// issue 8656
   206  	`package p; func f() (a b string /* ERROR "missing ','" */ , ok bool)`,
   207  
   208  	// issue 9639
   209  	`package p; var x /* ERROR "missing variable type or initialization" */ , y, z;`,
   210  	`package p; const x /* ERROR "missing constant value" */ ;`,
   211  	`package p; const x /* ERROR "missing constant value" */ int;`,
   212  	`package p; const (x = 0; y; z /* ERROR "missing constant value" */ int);`,
   213  
   214  	// issue 12437
   215  	`package p; var _ = struct { x int, /* ERROR "expected ';', found ','" */ }{};`,
   216  	`package p; var _ = struct { x int, /* ERROR "expected ';', found ','" */ y float }{};`,
   217  
   218  	// issue 11611
   219  	`package p; type _ struct { int, } /* ERROR "expected 'IDENT', found '}'" */ ;`,
   220  	`package p; type _ struct { int, float } /* ERROR "expected type, found '}'" */ ;`,
   221  
   222  	// issue 13475
   223  	`package p; func f() { if true {} else ; /* ERROR "expected if statement or block" */ }`,
   224  	`package p; func f() { if true {} else defer /* ERROR "expected if statement or block" */ f() }`,
   225  }
   226  
   227  // invalidNoTParamErrs holds invalid source code examples annotated with the
   228  // error messages produced when ParseTypeParams is not set.
   229  var invalidNoTParamErrs = []string{
   230  	`package p; type _[_ any /* ERROR "expected ']', found any" */ ] int; var _ = T[]{}`,
   231  	`package p; type T[P any /* ERROR "expected ']', found any" */ ] = T0`,
   232  	`package p; var _ func[ /* ERROR "expected '\(', found '\['" */ T any](T)`,
   233  	`package p; func _[ /* ERROR "expected '\(', found '\['" */ ]()`,
   234  	`package p; type _[A, /* ERROR "unexpected comma" */] struct{ A }`,
   235  	`package p; func _[ /* ERROR "expected '\(', found '\['" */ type P, *Q interface{}]()`,
   236  
   237  	`package p; func (T) _[ /* ERROR "expected '\(', found '\['" */ A, B any](a A) B`,
   238  	`package p; func (T) _[ /* ERROR "expected '\(', found '\['" */ A, B C](a A) B`,
   239  	`package p; func (T) _[ /* ERROR "expected '\(', found '\['" */ A, B C[A, B]](a A) B`,
   240  
   241  	`package p; func(*T[ /* ERROR "missing ',' in parameter list" */ e, e]) _()`,
   242  }
   243  
   244  // invalidTParamErrs holds invalid source code examples annotated with the
   245  // error messages produced when ParseTypeParams is set.
   246  var invalidTParamErrs = []string{
   247  	`package p; type _[_ any] int; var _ = T[] /* ERROR "expected operand" */ {}`,
   248  	`package p; var _ func[ /* ERROR "must have no type parameters" */ T any](T)`,
   249  	`package p; func _[]/* ERROR "empty type parameter list" */()`,
   250  
   251  	// TODO(rfindley) a better location would be after the ']'
   252  	`package p; type _[A /* ERROR "all type parameters must be named" */ ,] struct{ A }`,
   253  
   254  	// TODO(rfindley) this error is confusing.
   255  	`package p; func _[type /* ERROR "all type parameters must be named" */ P, *Q interface{}]()`,
   256  
   257  	`package p; func (T) _[ /* ERROR "must have no type parameters" */ A, B any](a A) B`,
   258  	`package p; func (T) _[ /* ERROR "must have no type parameters" */ A, B C](a A) B`,
   259  	`package p; func (T) _[ /* ERROR "must have no type parameters" */ A, B C[A, B]](a A) B`,
   260  
   261  	`package p; func(*T[e, e /* ERROR "e redeclared" */ ]) _()`,
   262  }
   263  
   264  func TestInvalid(t *testing.T) {
   265  	t.Run("no tparams", func(t *testing.T) {
   266  		for _, src := range invalids {
   267  			checkErrors(t, src, src, DeclarationErrors|AllErrors|typeparams.DisallowParsing, true)
   268  		}
   269  		for _, src := range validWithTParamsOnly {
   270  			checkErrors(t, src, src, DeclarationErrors|AllErrors|typeparams.DisallowParsing, true)
   271  		}
   272  		for _, src := range invalidNoTParamErrs {
   273  			checkErrors(t, src, src, DeclarationErrors|AllErrors|typeparams.DisallowParsing, true)
   274  		}
   275  	})
   276  	t.Run("tparams", func(t *testing.T) {
   277  		for _, src := range invalids {
   278  			checkErrors(t, src, src, DeclarationErrors|AllErrors, true)
   279  		}
   280  		for _, src := range invalidTParamErrs {
   281  			checkErrors(t, src, src, DeclarationErrors|AllErrors, true)
   282  		}
   283  	})
   284  }
   285
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