fx.OnStart, fx.OnStop doesn't work with named dependencies (using fx.ResultTags)
advanderveer opened this issue · 3 comments
Describe the bug
Given the examples of fx.OnStart/fx.OnStop I would expect the following code to work:
package main
import (
"database/sql"
"fmt"
"github.com/jackc/pgx/v4"
"github.com/jackc/pgx/v4/stdlib"
"go.uber.org/fx"
"golang.org/x/net/context"
)
func connect() *sql.DB {
return stdlib.OpenDB(pgx.ConnConfig{ /* usual connection params */ })
}
func main() {
fx.New(
fx.Provide(
fx.Annotate(connect,
fx.OnStart(func(ctx context.Context, ro *sql.DB) error { return ro.PingContext(ctx) }),
fx.ResultTags(`name:"ro"`)),
fx.Annotate(connect,
fx.OnStart(func(ctx context.Context, rw *sql.DB) error { return rw.PingContext(ctx) }),
fx.ResultTags(`name:"rw"`)),
),
fx.Invoke(func(db struct {
fx.In
RO *sql.DB `name:"ro"`
RW *sql.DB `name:"rw"`
}) {
fmt.Printf("invoke: %p %p\n", db.RO, db.RW)
}),
).Run()
}will result in the following error:
[Fx] PROVIDE *sql.DB[name = "ro"] <= fx.Annotate(main.connect(), fx.ResultTags(["name:\"ro\""])
[Fx] PROVIDE *sql.DB[name = "rw"] <= fx.Annotate(main.connect(), fx.ResultTags(["name:\"rw\""])
[Fx] PROVIDE fx.Lifecycle <= go.uber.org/fx.New.func1()
[Fx] PROVIDE fx.Shutdowner <= go.uber.org/fx.(*App).shutdowner-fm()
[Fx] PROVIDE fx.DotGraph <= go.uber.org/fx.(*App).dotGraph-fm()
[Fx] INVOKE main.main.func3()
[Fx] ERROR fx.Invoke(main.main.func3()) called from:
main.main
/Users/adam/Documents/Projects/github.com/crewlinker/core/fxbug/main.go:28
runtime.main
/usr/local/go/src/runtime/proc.go:250
Failed: could not build arguments for function "main".main.func3
/Users/adam/Documents/Projects/github.com/crewlinker/core/fxbug/main.go:28:
failed to build *sql.DB[name="ro"]:
missing dependencies for function "main".connect
/Users/adam/Documents/Projects/github.com/crewlinker/core/fxbug/main.go:13:
missing type:
- *sql.DB (did you mean to Provide it?)
[Fx] ERROR Failed to start: could not build arguments for function "main".main.func3
/Users/adam/Documents/Projects/github.com/crewlinker/core/fxbug/main.go:28:
failed to build *sql.DB[name="ro"]:
missing dependencies for function "main".connect
/Users/adam/Documents/Projects/github.com/crewlinker/core/fxbug/main.go:13:
missing type:
- *sql.DB (did you mean to Provide it?)
exit status 1
This makes me think that should provide the fx.OnStart param with more information about which *sql.DB the hooks applies to. But the following also doesn't work:
package main
import (
"database/sql"
"fmt"
"github.com/jackc/pgx/v4"
"github.com/jackc/pgx/v4/stdlib"
"go.uber.org/fx"
"golang.org/x/net/context"
)
func connect() *sql.DB {
return stdlib.OpenDB(pgx.ConnConfig{ /* usual connection params */ })
}
func main() {
fx.New(
fx.Provide(
fx.Annotate(connect,
fx.OnStart(func(ctx context.Context, db struct {
fx.In
RO *sql.DB `name:"ro"`
}) error {
return db.RO.PingContext(ctx)
}),
fx.ResultTags(`name:"ro"`)),
fx.Annotate(connect,
fx.OnStart(func(ctx context.Context, db struct {
fx.In
RW *sql.DB `name:"rw"`
}) error {
return db.RW.PingContext(ctx)
}),
fx.ResultTags(`name:"rw"`)),
),
fx.Invoke(func(db struct {
fx.In
RO *sql.DB `name:"ro"`
RW *sql.DB `name:"rw"`
}) {
fmt.Printf("invoke: %p %p\n", db.RO, db.RW)
}),
).Run()
}But this doesn't work either, it complains about cycle in the dependency graph:
[Fx] PROVIDE *sql.DB[name = "ro"] <= fx.Annotate(main.connect(), fx.ResultTags(["name:\"ro\""])
[Fx] PROVIDE *sql.DB[name = "rw"] <= fx.Annotate(main.connect(), fx.ResultTags(["name:\"rw\""])
[Fx] PROVIDE fx.Lifecycle <= go.uber.org/fx.New.func1()
[Fx] PROVIDE fx.Shutdowner <= go.uber.org/fx.(*App).shutdowner-fm()
[Fx] PROVIDE fx.DotGraph <= go.uber.org/fx.(*App).dotGraph-fm()
[Fx] INVOKE main.main.func3()
[Fx] ERROR fx.Invoke(main.main.func3()) called from:
main.main
/Users/adam/Documents/Projects/github.com/crewlinker/core/fxbug/main.go:38
runtime.main
/usr/local/go/src/runtime/proc.go:250
Failed: cycle detected in dependency graph:
func(struct { In dig.In; Hook0 struct { In dig.In; Lifecycle fx.Lifecycle; Field1 struct { dig.In; RO *sql.DB "name:\"ro\"" } } }) struct { Out dig.Out; Field0 *sql.DB "name:\"ro\"" } provided by "main".connect (/Users/adam/Documents/Projects/github.com/crewlinker/core/fxbug/main.go:13)
depends on func(struct { In dig.In; Hook0 struct { In dig.In; Lifecycle fx.Lifecycle; Field1 struct { dig.In; RO *sql.DB "name:\"ro\"" } } }) struct { Out dig.Out; Field0 *sql.DB "name:\"ro\"" } provided by "main".connect (/Users/adam/Documents/Projects/github.com/crewlinker/core/fxbug/main.go:13)
[Fx] ERROR Failed to start: cycle detected in dependency graph:
func(struct { In dig.In; Hook0 struct { In dig.In; Lifecycle fx.Lifecycle; Field1 struct { dig.In; RO *sql.DB "name:\"ro\"" } } }) struct { Out dig.Out; Field0 *sql.DB "name:\"ro\"" } provided by "main".connect (/Users/adam/Documents/Projects/github.com/crewlinker/core/fxbug/main.go:13)
depends on func(struct { In dig.In; Hook0 struct { In dig.In; Lifecycle fx.Lifecycle; Field1 struct { dig.In; RO *sql.DB "name:\"ro\"" } } }) struct { Out dig.Out; Field0 *sql.DB "name:\"ro\"" } provided by "main".connect (/Users/adam/Documents/Projects/github.com/crewlinker/core/fxbug/main.go:13)
exit status 1
To Reproduce
See the code above
Expected behavior
I expect that named dependencies can also have lifecycle annotations
Additional context
Thanks for reporting this issue. We'll look into this issue shortly.
Internal Ref: GO-1661.
cc @tchung1118
Thank you for the fix and releasing this in the latest version. I finally got around to testing it today. I'm not sure it is intended but the obvious less-verbose method described in the first code snippet does not work. But the second approach in my second snippet does work. So this can be closed as a blocker to use the annotations. But maybe another issue is appropriate to make it less verbose?
Hey, sorry I missed this. Yeah, I think making it less verbose could be a valid improvement on this (as a syntactic sugar), but meanwhile we can probably close this because those annotations do work with other annotations now.