csv: implement --append

The csv subcommand can now append data to the end of a table found in
range. Fixes #6.

See: https://developers.google.com/sheets/api/reference/rest/v4/spreadsheets.values/append

To append the contents of data.csv to the end of Sheet1, for example:

$ cat data.csv | gsheet --id SHEETS_DOC_ID --range Sheet1 --append

cmd/gsheet/cli.go

@@ -30,6 +30,10 @@ var app = &cli.App{
 					Name:  "range",
 					Usage: "Sheet range to update or get (A1 notation)",
 				},
+                &cli.BoolFlag{
+                    Name: "append",
+                    Usage: "If set, append to end of any data in range",
+                },
 				&cli.StringFlag{
 					Name:  "sep",
 					Value: ",",

cmd/gsheet/sheets.go

@@ -9,16 +9,16 @@ import (
 )
 
 func newSheetAction(c *cli.Context) error {
-    if c.String("id") == "" {
-        return fmt.Errorf("The --id flag is required")
-    }
+	if c.String("id") == "" {
+		return fmt.Errorf("The --id flag is required")
+	}
 	return sheetSvc.NewSheet(c.String("id"), c.String("name"))
 }
 
 func deleteSheetAction(c *cli.Context) error {
-    if c.String("id") == "" {
-        return fmt.Errorf("The --id flag is required")
-    }
+	if c.String("id") == "" {
+		return fmt.Errorf("The --id flag is required")
+	}
 	return sheetSvc.DeleteSheet(c.String("id"), c.String("name"))
 }
 
@@ -56,11 +56,21 @@ func rangeSheetAction(c *cli.Context) error {
 	} else {
 		// otherwise stdin is connected to a pipe or file
 		// send data
-		resp, err := sheetSvc.UpdateRangeCSV(c.String("id"), c.String("range"), os.Stdin)
-		if err != nil {
-			return err
+		if c.Bool("append") {
+			// append
+			resp, err := sheetSvc.AppendRangeCSV(c.String("id"), c.String("range"), os.Stdin)
+			if err != nil {
+				return err
+			}
+			fmt.Printf("Updated %d cells\n", resp.Updates.UpdatedCells)
+		} else {
+			// overwrite
+			resp, err := sheetSvc.UpdateRangeCSV(c.String("id"), c.String("range"), os.Stdin)
+			if err != nil {
+				return err
+			}
+			fmt.Printf("Updated %d cells\n", resp.UpdatedCells)
 		}
-		fmt.Printf("Updated %d cells\n", resp.UpdatedCells)
 	}
 	return nil
 }

gsheets/integration_test.go

@@ -51,6 +51,7 @@ func TestSheetIntegration(t *testing.T) {
 	// - (Create new spreadsheet with drive package)
 	// - Create new sheet
 	// - Update data in sheet via csv
+    // - Append data to sheet
 	// - Clear sheet
 	// - Delete sheet
 	// - (Use drive package to delete document)
@@ -103,6 +104,25 @@ func TestSheetIntegration(t *testing.T) {
 		t.Fail()
 	}
 
+    // test append
+    appendResp, err := svcSheet.AppendRangeCSV(testfile.Id, "TEST", strings.NewReader(testData))
+    if err != nil {
+        t.Fatal(err)
+    }
+    if appendResp.Updates.UpdatedCells != 12 {
+        t.Fatal("Unexpected number of cells updated")
+    }
+	vals, err = svcSheet.GetRangeCSV(testfile.Id, "TEST")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.ReplaceAll(string(vals), "\n", "") !=
+		strings.ReplaceAll(testData + testData, "\n", "") {
+		t.Log("Updated data does not match test data")
+		t.Log(vals, []byte(testData))
+		t.Fail()
+	}
+
 	err = svcSheet.Clear(testfile.Id, "TEST")
 	if err != nil {
 		t.Fatal(err)

gsheets/sheets.go

@@ -26,6 +26,7 @@ type ssService interface {
 
 // Define an interface so we can mock the SpreadsheetsValuesService if we need to
 type valueService interface {
+	Append(string, string, *sheets.ValueRange) *sheets.SpreadsheetsValuesAppendCall
 	BatchGet(string) *sheets.SpreadsheetsValuesBatchGetCall
 	BatchUpdate(string, *sheets.BatchUpdateValuesRequest) *sheets.SpreadsheetsValuesBatchUpdateCall
 	BatchClear(string, *sheets.BatchClearValuesRequest) *sheets.SpreadsheetsValuesBatchClearCall
@@ -60,9 +61,9 @@ func (svc *Service) SpreadsheetsService() *sheets.SpreadsheetsService {
 
 // NewSheet creates a new sheet on spreadsheet identified by 'id'
 func (svc *Service) NewSheet(id, title string) error {
-    if id == "" {
-        return errors.New("id cannot be empty")
-    }
+	if id == "" {
+		return errors.New("id cannot be empty")
+	}
 	_, err := svc.sheet.BatchUpdate(id, &sheets.BatchUpdateSpreadsheetRequest{
 		Requests: []*sheets.Request{
 			&sheets.Request{
@@ -99,9 +100,9 @@ func (svc *Service) SheetFromTitle(id, title string) (*int64, error) {
 // DeleteSheet deletes the sheet with 'title' from spreadsheet doc identified
 // by 'id'
 func (svc *Service) DeleteSheet(id, title string) error {
-    if id == "" {
-        return errors.New("id cannot be empty")
-    }
+	if id == "" {
+		return errors.New("id cannot be empty")
+	}
 	// find sheet matching title
 	sheetId, err := svc.SheetFromTitle(id, title)
 	if err != nil {
@@ -213,12 +214,8 @@ func (svc *Service) UpdateRangeRaw(id, a1Range string, values [][]interface{}) (
 	return resp.Responses[0], nil
 }
 
-// UpdateRangeStrings update values in 'a1Range' in the spreadsheet doc
-// identified by 'id' to 'values'.
-// Values will be parsed by Google Sheets as if they were typed in by the user
-// (so strings containing numerals may be converted to numbers, etc.)
-func (svc *Service) UpdateRangeStrings(id, a1Range string, values [][]string) (*sheets.UpdateValuesResponse, error) {
-
+// cast [][]string to [][]interface{} for passing csv data to Google Sheets
+func strToInterface(values [][]string) [][]interface{} {
 	// make a [][]interface{} to hold typecast values
 	var vals = make([][]interface{}, len(values))
 	for i := range vals {
@@ -230,10 +227,59 @@ func (svc *Service) UpdateRangeStrings(id, a1Range string, values [][]string) (*
 			vals[r][c] = v
 		}
 	}
+	return vals
+}
+
+// AppendRangeStrings appends 'values' to any table found in 'a1Range' in the
+// spreadsheet doc identified by 'id'
+// Values will be parsed by Google Sheets as if they were typed in by the user
+// (so strings containing numerals may be converted to numbers, etc.)
+// see: https://developers.google.com/sheets/api/reference/rest/v4/spreadsheets.values/append
+func (svc *Service) AppendRangeStrings(id, a1Range string, values [][]string) (*sheets.AppendValuesResponse, error) {
+
+	// cast strings to interfaces
+	vals := strToInterface(values)
+
+	resp, err := svc.values.Append(id, a1Range, &sheets.ValueRange{
+		Values: vals,
+	}).
+        ValueInputOption("USER_ENTERED").
+        Context(svc.ctx).
+        Do()
+    if err != nil {
+        return nil, err
+    }
+	return resp, nil
+}
+
+// AppendRangeCSV appends 'values' to any table found in 'a1Range' in the
+// spreadsheet doc identified by 'id'
+// 'values' is an io.Reader which supplies text in csv format.
+// Values will be parsed by Google Sheets as if they were typed in by the user
+// (so strings containing numerals may be converted to numbers, etc.)
+func (svc *Service) AppendRangeCSV(id, a1Range string, values io.Reader) (*sheets.AppendValuesResponse, error) {
+	csvR := csv.NewReader(values)
+	csvR.FieldsPerRecord = -1 // disable field checks
+	csvR.Comma = svc.Sep
+	rows, err := csvR.ReadAll()
+	if err != nil {
+		return nil, err
+	}
+	return svc.AppendRangeStrings(id, a1Range, rows)
+}
+
+// UpdateRangeStrings update values in 'a1Range' in the spreadsheet doc
+// identified by 'id' to 'values'.
+// Values will be parsed by Google Sheets as if they were typed in by the user
+// (so strings containing numerals may be converted to numbers, etc.)
+func (svc *Service) UpdateRangeStrings(id, a1Range string, values [][]string) (*sheets.UpdateValuesResponse, error) {
+
+	// cast strings to interfaces
+	vals := strToInterface(values)
 
 	resp, err := svc.values.BatchUpdate(id, &sheets.BatchUpdateValuesRequest{
 		Data: []*sheets.ValueRange{
-			&sheets.ValueRange{
+			{
 				MajorDimension: "ROWS",
 				Range:          a1Range,
 				Values:         vals,

readme.adoc

@@ -14,7 +14,7 @@ With `gsheet` you can:
 - Pipe csv data from stdin to a Google Sheet range +
 `cat data.csv | gsheet csv --id 1o88FhvAXg8Q_ZMFudQLuZ1ShsigbAgJ --range 'Sheet1'`
 - Pipe csv data from a Google Sheet range to stdout +
-`gsheet csv --id 1o88FhvAXg8Q_ZMFudQLuZ1ShsigbAgJ --range "'Sheet!'A1:D20" > data.csv`
+`gsheet csv --id 1o88FhvAXg8Q_ZMFudQLuZ1ShsigbAgJ --range 'Sheet!A1:D20' > data.csv`
 - Clear a Google Sheet range +
 `gsheet clear --id 1o88FhvAXg8Q_ZMFudQLuZ1ShsigbAgJ --range Sheet2`
 - Create and delete sheets of a Spreadsheet document +
@@ -98,7 +98,9 @@ Remember that for any of the commands to work you must have the GOOGLE_APPLICATI
 === Sheet commands
 ==== csv and clear
 
-The `csv` command is the heart of `gsheet`. If you pipe csv data to it on std input, it sends the data to the specified range of the Sheets document identified by the `--id` flag. If you don't connect stdin to a pipe, then it will read the specified range and output it to stdout in csv format.
+The `csv` command is the heart of `gsheet`. If you pipe csv data to it on std input, it sends the data to the specified range of the Sheets document identified by the `--id` flag. If you pass the `--append` flag, data will be appended to the last row of data found in range.
+
+If you don't connect stdin to a pipe, then it will read the specified range and output it to stdout in csv format.
 
 NOTE: `csv` does not clear the range before updating data in a Sheets document. If the piped data is smaller (fewer rows or columns) than the specified range, then any pre-existing data in the spreadsheet will remain after the update. Use `gsheet clear` to clear a range.
 
@@ -108,6 +110,9 @@ NOTE: `csv` does not clear the range before updating data in a Sheets document.
 gsheet --id SHEETS_DOC_ID clear --range Sheet1
 cat data.csv | gsheet --id SHEETS_DOC_ID --range Sheet1
 
+# Append the contents of data.csv after the lat line of existing data in Sheet1
+cat data.csv | gsheet --id SHEETS_DOC_ID --range Sheet1 --append
+
 # Read a specific range of a sheet to output.csv
 # (You can always single quote sheet names and include the exclamation point in
 # the single quotes so that the shell doesn't try to interpret it.)
@@ -120,7 +125,7 @@ An existing sheet can be sorted by any (single) column in either descending (def
 
 [source,sh]
 ----
-# Sort sheet by B coloumn in ascending order
+# Sort sheet by B column in ascending order
 sort --id SHEET_NAME -name Sheet1 --column=1 --asc
 ----
 
@@ -213,8 +218,8 @@ All of the Sheets related functions are in the `gsheets` package (`gsheets/sheet
 
 Online godoc documentation for the packages can be found here:
 
-- https://pkg.go.dev/github.com/cristoper/gsheet@v0.1.0/gdrive
-- https://pkg.go.dev/github.com/cristoper/gsheet@v0.1.0/gsheets
+- https://pkg.go.dev/github.com/cristoper/gsheet/gdrive
+- https://pkg.go.dev/github.com/cristoper/gsheet/gsheets
 
 For a quick-and-dirty example of how to use the packages look at the `integration_test.go` file included in each package.