ensure: tweaks to align no-vendor behavior and verbose/dry-run logging (#1039)

* ensure: tweaks to align no-vendor behavior and verbose/dry-run logging
* ensure: dry-run: always log lock diff
* log PrintPreparedActions to ctx Out not Err

Author: jmank88

Diff for: cmd/dep/ensure.go

@@ -223,15 +223,15 @@ func (cmd *ensureCommand) runDefault(ctx *dep.Ctx, args []string, p *dep.Project
 
 	if p.Lock != nil && bytes.Equal(p.Lock.InputHash(), solver.HashInputs()) {
 		// Memo matches, so there's probably nothing to do.
+		if ctx.Verbose {
+			ctx.Out.Printf("%s was already in sync with imports and %s\n", dep.LockName, dep.ManifestName)
+		}
+
 		if cmd.noVendor {
 			// The user said not to touch vendor/, so definitely nothing to do.
 			return nil
 		}
 
-		if ctx.Verbose {
-			ctx.Out.Printf("%s was already in sync with imports and %s, recreating vendor/ directory", dep.LockName, dep.ManifestName)
-		}
-
 		// TODO(sdboyer) The desired behavior at this point is to determine
 		// whether it's necessary to write out vendor, or if it's already
 		// consistent with the lock. However, we haven't yet determined what
@@ -244,8 +244,7 @@ func (cmd *ensureCommand) runDefault(ctx *dep.Ctx, args []string, p *dep.Project
 		}
 
 		if cmd.dryRun {
-			ctx.Out.Printf("Would have populated vendor/ directory from %s", dep.LockName)
-			return nil
+			return sw.PrintPreparedActions(ctx.Out, ctx.Verbose)
 		}
 
 		logger := ctx.Err
@@ -261,12 +260,16 @@ func (cmd *ensureCommand) runDefault(ctx *dep.Ctx, args []string, p *dep.Project
 		return errors.Wrap(err, "ensure Solve()")
 	}
 
-	sw, err := dep.NewSafeWriter(nil, p.Lock, dep.LockFromSolution(solution), dep.VendorOnChanged)
+	vendorBehavior := dep.VendorOnChanged
+	if cmd.noVendor {
+		vendorBehavior = dep.VendorNever
+	}
+	sw, err := dep.NewSafeWriter(nil, p.Lock, dep.LockFromSolution(solution), vendorBehavior)
 	if err != nil {
 		return err
 	}
 	if cmd.dryRun {
-		return sw.PrintPreparedActions(ctx.Out)
+		return sw.PrintPreparedActions(ctx.Out, ctx.Verbose)
 	}
 
 	logger := ctx.Err
@@ -292,14 +295,7 @@ func (cmd *ensureCommand) runVendorOnly(ctx *dep.Ctx, args []string, p *dep.Proj
 	}
 
 	if cmd.dryRun {
-		ctx.Out.Printf("Would have populated vendor/ directory from %s", dep.LockName)
-		if ctx.Verbose {
-			err := sw.PrintPreparedActions(ctx.Err)
-			if err != nil {
-				return errors.WithMessage(err, "prepared actions")
-			}
-		}
-		return nil
+		return sw.PrintPreparedActions(ctx.Out, ctx.Verbose)
 	}
 
 	logger := ctx.Err
@@ -394,7 +390,7 @@ func (cmd *ensureCommand) runUpdate(ctx *dep.Ctx, args []string, p *dep.Project,
 		return err
 	}
 	if cmd.dryRun {
-		return sw.PrintPreparedActions(ctx.Out)
+		return sw.PrintPreparedActions(ctx.Out, ctx.Verbose)
 	}
 
 	logger := ctx.Err
@@ -648,7 +644,7 @@ func (cmd *ensureCommand) runAdd(ctx *dep.Ctx, args []string, p *dep.Project, sm
 	}
 
 	if cmd.dryRun {
-		return sw.PrintPreparedActions(ctx.Out)
+		return sw.PrintPreparedActions(ctx.Out, ctx.Verbose)
 	}
 
 	logger := ctx.Err

Diff for: txn_writer.go

@@ -418,24 +418,30 @@ fail:
 }
 
 // PrintPreparedActions logs the actions a call to Write would perform.
-func (sw *SafeWriter) PrintPreparedActions(output *log.Logger) error {
+func (sw *SafeWriter) PrintPreparedActions(output *log.Logger, verbose bool) error {
 	if sw.HasManifest() {
-		output.Printf("Would have written the following %s:\n", ManifestName)
-		m, err := sw.Manifest.MarshalTOML()
-		if err != nil {
-			return errors.Wrap(err, "ensure DryRun cannot serialize manifest")
+		if verbose {
+			m, err := sw.Manifest.MarshalTOML()
+			if err != nil {
+				return errors.Wrap(err, "ensure DryRun cannot serialize manifest")
+			}
+			output.Printf("Would have written the following %s:\n%s\n", ManifestName, string(m))
+		} else {
+			output.Printf("Would have written %s.\n", ManifestName)
 		}
-		output.Println(string(m))
 	}
 
 	if sw.writeLock {
 		if sw.lockDiff == nil {
-			output.Printf("Would have written the following %s:\n", LockName)
-			l, err := sw.lock.MarshalTOML()
-			if err != nil {
-				return errors.Wrap(err, "ensure DryRun cannot serialize lock")
+			if verbose {
+				l, err := sw.lock.MarshalTOML()
+				if err != nil {
+					return errors.Wrap(err, "ensure DryRun cannot serialize lock")
+				}
+				output.Printf("Would have written the following %s:\n%s\n", LockName, string(l))
+			} else {
+				output.Printf("Would have written %s.\n", LockName)
 			}
-			output.Println(string(l))
 		} else {
 			output.Printf("Would have written the following changes to %s:\n", LockName)
 			diff, err := formatLockDiff(*sw.lockDiff)
@@ -447,9 +453,13 @@ func (sw *SafeWriter) PrintPreparedActions(output *log.Logger) error {
 	}
 
 	if sw.writeVendor {
-		output.Println("Would have written the following projects to the vendor directory:")
-		for _, project := range sw.lock.Projects() {
-			output.Println(project)
+		if verbose {
+			output.Printf("Would have written the following %d projects to the vendor directory:\n", len(sw.lock.Projects()))
+			for _, project := range sw.lock.Projects() {
+				output.Println(project)
+			}
+		} else {
+			output.Printf("Would have written %d projects to the vendor directory.\n", len(sw.lock.Projects()))
 		}
 	}