flow: more improvements to error processing and printing, especially …

…os.Exec (#384)

Co-authored-by: Tony Worm <[email protected]>

flow/cmd/run.go

@@ -31,6 +31,7 @@ func prepFlow(R *Runtime, val cue.Value) (*flow.Flow, error) {
 	c.Stdout = os.Stdout
 	c.Stderr = os.Stderr
 	c.Verbosity = R.Flags.Verbosity
+	c.ShowErrors = R.Flags.AllErrors
 
 	// how to inject tags into original value
 	// fill / return value
@@ -177,7 +178,7 @@ func printFinalContext(ctx *flowctx.Context) error {
 	fmt.Println("\n\n======= final =========")
 
 	return yagu.PrintAsTable(
-		[]string{"Task", "Deps", "Time"},
+		[]string{"Name", "Task", "Deps", "Time", "Err"},
 		func(table *tablewriter.Table) ([][]string, error) {
 			var rows = make([][]string, 0, len(ti))
 			// fill with data
@@ -204,7 +205,27 @@ func printFinalContext(ctx *flowctx.Context) error {
 					deps = fmt.Sprint(ps)
 				}
 
-				row := []string{t.ID, deps, fmt.Sprint(l)}
+				tt := ""
+				attrs := t.Orig.Attributes(cue.ValueAttr)
+				for _, a := range attrs {
+					if a.Name() == "task" {
+						tt = fmt.Sprint(a)
+						break
+					}
+				}
+
+				// fmt.Println(t.Final)
+				final := t.CueTask.Value()
+				// fmt.Println(final)
+
+				err := ""
+				if t.Error != nil {
+					err = fmt.Sprint(t.Error)
+				} else if e := final.LookupPath(cue.ParsePath("error")); e.Exists() {
+					err = fmt.Sprint(e)
+				}
+
+				row := []string{t.ID, tt, deps, fmt.Sprint(l), err}
 				rows = append(rows, row)
 			}
 

flow/context/context.go

@@ -30,6 +30,9 @@ type Context struct {
 	// debug / internal
 	Verbosity int
 
+	// print errors, even if we continue in their presence
+	ShowErrors bool
+
 	Middlewares  []Middleware
 	TaskRegistry *sync.Map
 
@@ -83,6 +86,7 @@ func Copy(ctx *Context) *Context {
 		Stderr: ctx.Stderr,
 
 		Verbosity: ctx.Verbosity,
+		ShowErrors: ctx.ShowErrors,
 
 		CUELock:  ctx.CUELock,
 		Mailbox:  ctx.Mailbox,

flow/tasker/tasker.go

@@ -121,17 +121,9 @@ func makeTask(ctx *flowctx.Context, node *hof.Node[any]) (cueflow.Runner, error)
 		// run the hof task
 		bt.AddTimeEvent("run.beg")
 		// (update)
-		value, err := T.Run(c)
+		value, rerr := T.Run(c)
 		bt.AddTimeEvent("run.end")
 
-		if err != nil {
-			err = fmt.Errorf("in %q\n%v", c.Value.Path(), cuetils.ExpandCueError(err))
-			// fmt.Println("RunnerRunc Error:", err)
-			c.Error = err
-			bt.Error = err
-			return err
-		}
-
 		if value != nil {
 			// fmt.Println("FILL:", taskId, c.Value.Path(), t.Value(), value)
 			bt.AddTimeEvent("fill.beg")
@@ -140,20 +132,31 @@ func makeTask(ctx *flowctx.Context, node *hof.Node[any]) (cueflow.Runner, error)
 			//  fmt.Println("FILL:", taskId, c.Value.Path(), value)
 			//}
 			err = t.Fill(value)
+			bt.Final = t.Value()
 			bt.AddTimeEvent("fill.end")
+
+			// fmt.Println("FILL:", taskId, c.Value.Path(), t.Value(), value)
 			if err != nil {
 				c.Error = err
 				bt.Error = err
 				return err
 			}
 
-			bt.Final = t.Value()
 			//if node.Hof.Flow.Print.Level > 0 && !node.Hof.Flow.Print.Before {
 			//  // pv := bt.Final.LookupPath(cue.ParsePath(node.Hof.Flow.Print.Path))
 			//  fmt.Printf("%s.%s: %# v\n", node.Hof.Path, node.Hof.Flow.Print.Path, value)
 			//}
 
 		}
+
+		if rerr != nil {
+			rerr = fmt.Errorf("in %q\n%v\n%+v", c.Value.Path(), cuetils.ExpandCueError(rerr), value)
+			// fmt.Println("RunnerRunc Error:", err)
+			c.Error = rerr
+			bt.Error = rerr
+			return rerr
+		}
+
 		return nil
 	}), nil
 }

flow/tasks/os/exec.go

@@ -95,7 +95,7 @@ func (T *Exec) Run(ctx *hofcontext.Context) (interface{}, error) {
 	//
 	// run command
 	//
-	err = cmd.Run()
+	rerr := cmd.Run()
 
 	// TODO, how to run in the background and wait for signal?
 
@@ -114,14 +114,15 @@ func (T *Exec) Run(ctx *hofcontext.Context) (interface{}, error) {
 	ret["exitcode"] = cmd.ProcessState.ExitCode()
 	ret["success"] = cmd.ProcessState.Success()
 
-	// fmt.Println("GOT HERE", err, v, ret)
 
-	if err != nil {
+	if rerr != nil {
+		ret["error"] = rerr.Error()
 		if doExit  {
-			return ret, err
+			fmt.Printf("In %v\n%v", v.Path(), ret)
+			return ret, rerr
+		} else if ctx.ShowErrors {
+			fmt.Printf("In %v\n%v", v.Path(), ret)
 		}
-
-		ret["error"] = err.Error()
 	}
 	return ret, nil
 }

flow/testdata/tasks/os/flow.cue

@@ -0,0 +1,5 @@
+tasks: {
+  @flow()
+	r: { filename: "in.txt", contents: string } @task(os.ReadFile)
+}
+

flow/testdata/tasks/os/golden.stdout

@@ -0,0 +1,6 @@
+Error in tasks | tasks: task failed: in "r"
+open in.txt: no such file or directory
+
+<nil>
+
+1 error(s) were encountered

flow/testdata/tasks/os/readfile_003.txt

@@ -11,4 +11,6 @@ tasks: {
 Error in tasks | tasks: task failed: in "r"
 open in.txt: no such file or directory
 
+<nil>
+
 1 error(s) were encountered