pkg/tool: improve error reporting
Bail early in case of unavailable fields.
Adds helper methods to internal/task for this purpose.
Fixes #243
Change-Id: I664e8b91e119929be9babce293af5a31ad550dd4
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/4483
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/internal/task/task.go b/internal/task/task.go
index b494a1a..a6e563c 100644
--- a/internal/task/task.go
+++ b/internal/task/task.go
@@ -21,6 +21,7 @@
"sync"
"cuelang.org/go/cue"
+ "cuelang.org/go/cue/errors"
)
// A Context provides context for running a task.
@@ -28,6 +29,61 @@
Context context.Context
Stdout io.Writer
Stderr io.Writer
+ Obj cue.Value
+ Err errors.Error
+}
+
+func (c *Context) Lookup(field string) cue.Value {
+ f := c.Obj.Lookup(field)
+ if !f.Exists() {
+ c.Err = errors.Append(c.Err, errors.Newf(c.Obj.Pos(),
+ "could not find field %q", field))
+ return cue.Value{}
+ }
+ if err := f.Err(); err != nil {
+ c.Err = errors.Append(c.Err, errors.Promote(err, "lookup"))
+ }
+ return f
+}
+
+func (c *Context) Int64(field string) int64 {
+ f := c.Obj.Lookup(field)
+ value, err := f.Int64()
+ if err != nil {
+ // TODO: use v for position for now, as f has not yet a
+ // position associated with it.
+ c.Err = errors.Append(c.Err, errors.Wrapf(err, c.Obj.Pos(),
+ "invalid integer argument for field %q", field))
+ return 0
+ }
+ return value
+}
+
+func (c *Context) String(field string) string {
+ f := c.Obj.Lookup(field)
+ value, err := f.String()
+ if err != nil {
+ // TODO: use v for position for now, as f has not yet a
+ // position associated with it.
+ c.Err = errors.Append(c.Err, errors.Wrapf(err, c.Obj.Pos(),
+ "invalid string argument for field %q", field))
+ c.Err = errors.Promote(err, "ddd")
+ return ""
+ }
+ return value
+}
+
+func (c *Context) Bytes(field string) []byte {
+ f := c.Obj.Lookup(field)
+ value, err := f.Bytes()
+ if err != nil {
+ // TODO: use v for position for now, as f has not yet a
+ // position associated with it.
+ c.Err = errors.Append(c.Err, errors.Wrapf(err, c.Obj.Pos(),
+ "invalid bytes argument for field %q", field))
+ return nil
+ }
+ return value
}
// A RunnerFunc creates a Runner.
@@ -42,7 +98,7 @@
// Runner runs given the current value and returns a new value which is to
// be unified with the original result.
- Run(ctx *Context, v cue.Value) (results interface{}, err error)
+ Run(ctx *Context) (results interface{}, err error)
}
// Register registers a task for cue commands.
