goose: read tests from testdata

Since tests are all written in terms of Go source, it makes tests easier
to write.  They still need to be arranged in a GOPATH for go build, but
tests that just call Generate can operate in-place because I've faked
the filesystem.

Reviewed-by: Tuo Shan <shantuo@google.com>
Reviewed-by: Herbie Ong <herbie@google.com>

internal/goose/testdata/Chain/foo/foo.go

@@ -0,0 +1,20 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println(injectFooBar())
+}
+
+type Foo int
+type FooBar int
+
+//goose:provide Set
+func provideFoo() Foo {
+	return 41
+}
+
+//goose:provide Set
+func provideFooBar(foo Foo) FooBar {
+	return FooBar(foo) + 1
+}

internal/goose/testdata/Chain/foo/foo_goose.go

@@ -0,0 +1,7 @@
+//+build gooseinject
+
+package main
+
+//goose:use Set
+
+func injectFooBar() FooBar

internal/goose/testdata/Chain/out.txt

@@ -0,0 +1 @@
+42

internal/goose/testdata/Chain/pkg

@@ -0,0 +1 @@
+foo

internal/goose/testdata/InjectInput/foo/foo.go

@@ -0,0 +1,21 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println(injectFooBar(40))
+}
+
+type Foo int
+type Bar int
+type FooBar int
+
+//goose:provide Set
+func provideBar() Bar {
+	return 2
+}
+
+//goose:provide Set
+func provideFooBar(foo Foo, bar Bar) FooBar {
+	return FooBar(foo) + FooBar(bar)
+}

internal/goose/testdata/InjectInput/foo/foo_goose.go

@@ -0,0 +1,7 @@
+//+build gooseinject
+
+package main
+
+//goose:use Set
+
+func injectFooBar(foo Foo) FooBar

internal/goose/testdata/InjectInput/out.txt

@@ -0,0 +1 @@
+42

internal/goose/testdata/InjectInput/pkg

@@ -0,0 +1 @@
+foo

internal/goose/testdata/InjectInputConflict/foo/foo.go

@@ -0,0 +1,23 @@
+package main
+
+import "fmt"
+
+func main() {
+	// I'm on the fence as to whether this should be an error (versus an
+	// override). For now, I will make it an error that can be relaxed
+	// later.
+	fmt.Println(injectBar(40))
+}
+
+type Foo int
+type Bar int
+
+//goose:provide Set
+func provideFoo() Foo {
+	return -888
+}
+
+//goose:provide Set
+func provideBar(foo Foo) Bar {
+	return 2
+}

internal/goose/testdata/InjectInputConflict/foo/foo_goose.go

@@ -0,0 +1,7 @@
+//+build gooseinject
+
+package main
+
+//goose:use Set
+
+func injectBar(foo Foo) Bar

internal/goose/testdata/InjectInputConflict/out.txt

@@ -0,0 +1 @@
+ERROR

internal/goose/testdata/InjectInputConflict/pkg

@@ -0,0 +1 @@
+foo

internal/goose/testdata/MissingUse/foo/foo.go

@@ -0,0 +1,14 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println(injectedMessage())
+}
+
+//goose:provide Set
+
+// provideMessage provides a friendly user greeting.
+func provideMessage() string {
+	return "Hello, World!"
+}

internal/goose/testdata/MissingUse/foo/foo_goose.go

@@ -0,0 +1,5 @@
+//+build gooseinject
+
+package main
+
+func injectedMessage() string

internal/goose/testdata/MissingUse/out.txt

@@ -0,0 +1 @@
+ERROR

internal/goose/testdata/MissingUse/pkg

@@ -0,0 +1 @@
+foo

internal/goose/testdata/NiladicIdentity/foo/foo.go

@@ -0,0 +1,14 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println(injectedMessage())
+}
+
+//goose:provide
+
+// provideMessage provides a friendly user greeting.
+func provideMessage() string {
+	return "Hello, World!"
+}

internal/goose/testdata/NiladicIdentity/foo/foo_goose.go

@@ -0,0 +1,7 @@
+//+build gooseinject
+
+package main
+
+//goose:use provideMessage
+
+func injectedMessage() string

internal/goose/testdata/NiladicIdentity/out.txt

@@ -0,0 +1 @@
+Hello, World!

internal/goose/testdata/NiladicIdentity/pkg

@@ -0,0 +1 @@
+foo

internal/goose/testdata/NoopBuild/foo/foo.go

@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("Hello, World!")
+}

internal/goose/testdata/NoopBuild/out.txt

@@ -0,0 +1 @@
+Hello, World!

internal/goose/testdata/NoopBuild/pkg

@@ -0,0 +1 @@
+foo

internal/goose/testdata/ReturnError/foo/foo.go

@@ -0,0 +1,22 @@
+package main
+
+import "errors"
+import "fmt"
+import "strings"
+
+func main() {
+	foo, err := injectFoo()
+	fmt.Println(foo) // should be zero, the injector should ignore provideFoo's return value.
+	if err == nil {
+		fmt.Println("<nil>")
+	} else {
+		fmt.Println(strings.Contains(err.Error(), "there is no Foo"))
+	}
+}
+
+type Foo int
+
+//goose:provide Set
+func provideFoo() (Foo, error) {
+	return 42, errors.New("there is no Foo")
+}

internal/goose/testdata/ReturnError/foo/foo_goose.go

@@ -0,0 +1,7 @@
+//+build gooseinject
+
+package main
+
+//goose:use Set
+
+func injectFoo() (Foo, error)

internal/goose/testdata/ReturnError/out.txt

@@ -0,0 +1,2 @@
+0
+true

internal/goose/testdata/ReturnError/pkg

@@ -0,0 +1 @@
+foo

internal/goose/testdata/TwoDeps/foo/foo.go

@@ -0,0 +1,26 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println(injectFooBar())
+}
+
+type Foo int
+type Bar int
+type FooBar int
+
+//goose:provide Set
+func provideFoo() Foo {
+	return 40
+}
+
+//goose:provide Set
+func provideBar() Bar {
+	return 2
+}
+
+//goose:provide Set
+func provideFooBar(foo Foo, bar Bar) FooBar {
+	return FooBar(foo) + FooBar(bar)
+}

internal/goose/testdata/TwoDeps/foo/foo_goose.go

@@ -0,0 +1,7 @@
+//+build gooseinject
+
+package main
+
+//goose:use Set
+
+func injectFooBar() FooBar

internal/goose/testdata/TwoDeps/out.txt

@@ -0,0 +1 @@
+42

internal/goose/testdata/TwoDeps/pkg

@@ -0,0 +1 @@
+foo