Small refinements (#1)

- Add testing to CI.
- Clarify that this isn’t an officially supported product.
- Clarify that this outputs ext JSON.
- Refine a couple error messages.

Author: FGasper

.github/workflows/test.yml

@@ -0,0 +1,25 @@
+on:
+  push:
+    branches:
+      - '*'
+    tags-ignore:
+      - '*'
+  pull_request:
+
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+
+    steps:
+      - run: uname -a
+      - run: ldconfig -p
+      - run: lsb_release -a
+
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Fetch Go
+        uses: actions/setup-go@v5
+
+      - name: Test
+        run: go test -v ./... -race

README.md

@@ -1,8 +1,12 @@
 # mongodump-parser
 
+This Repository is **NOT** an officially supported MongoDB product.
+
 This simple tool reads a
 [mongodump](https://www.mongodb.com/docs/database-tools/mongodump/) archive
 on its standard input, parses the archive’s header & collection metadata,
-then writes the result as a JSON document to standard output.
+then writes the result as a
+[MongoDB Extended JSON](https://www.mongodb.com/docs/manual/reference/mongodb-extended-json/)
+document to standard output.
 
 To build it, just run `go build`.

main.go

@@ -37,7 +37,7 @@ func main() {
 	var cmd = cli.Command{
 		Name:        "mongodump-parser",
 		Usage:       "parse mongodump archive files",
-		Description: wordwrap.WrapString("This tool reads a mongodump archive file from standard input, parses its header, then outputs the parse to standard output. This lets you see an archive’s contents without actually restoring it.", uint(colWidth-4)),
+		Description: wordwrap.WrapString("This tool reads a mongodump archive file from standard input, parses its header, then outputs the parse to standard output in MongoDB Extended JSON. This lets you see an archive’s contents without actually restoring it.", uint(colWidth-4)),
 		Action: func(_ context.Context, cmd *cli.Command) error {
 			return run(cmd)
 		},
@@ -71,7 +71,7 @@ func run(cmd *cli.Command) error {
 func getReport(input io.Reader, errOut io.Writer) (Report, error) {
 	err := checkMagicBytes(input)
 	if err != nil {
-		return Report{}, err
+		return Report{}, errors.Wrap(err, "this does not appear to be a mongodump archive")
 	}
 
 	header := bson.D{}
@@ -152,7 +152,7 @@ func checkMagicBytes(input io.Reader) error {
 
 	magicNum := binary.LittleEndian.Uint32(magicBytes[:])
 	if magicNum != archive.MagicNumber {
-		return fmt.Errorf("expected magic number header (%v, %d); should be %d", magicBytes, magicNum, archive.MagicNumber)
+		return fmt.Errorf("unexpected magic number header (%v, %d); should be %d", magicBytes, magicNum, archive.MagicNumber)
 	}
 
 	return nil