Merge pull request #19 from zostay/many-date-fields

More parsing options for date and address fields, better Get error handling

Changes.md

@@ -0,0 +1,67 @@
+WIP  TBD
+
+ * On `header.ErrManyFields` failure, `(*header.Header).Get()` now returns the value of the first field found with the error.
+ * Add a `header.ParseTime()` function which provides the same time parsing facilities that `(*header.Header).GetTime()` and `(*header.Header).GetDate()` use.
+ * Add a `header.ParseAddressList()`function which provides the same `addr.AddressList` parsing facilities that are built in to the various address parsing methods of `header.Header`.
+
+v2.2.1  2023-01-30
+
+ * Bugfix: Fixed a typo in `header.ErrNoSuchField` error message.
+
+v2.2.0  2023-01-30
+
+ * Deprecation: The contents of the `walker` package are deprecated and will be removed in a future release. Use the features of the `walk` package instead.
+ * Add the `walk` package.
+ * Add `walk.AndProcess` and `walk.Processor` to handle walking a message part tree with the goal of generic message processing.
+ * Add `walk.AndTransform` and `walk.Transformer` to handle walking a message part tree, which is a process tool that aids with message transformation.
+ * Add `walk.AndProcessSingle` to process single parts of a message.
+ * Add `walk.AndProcessMultipart` to process multipart parts of a message.
+ * Add `message.NewBuffer` to copy message.Part into a message.Buffer.
+ * Add `message.NewBlankBuffer` to copy `message.Part` into a `message.Buffer`, but without body content or sub-parts.
+ * Add `(*message.Buffer).AddBuffers` method for convenience.
+
+v2.1.0  2023-01-27
+
+ * Deprecation: The `OpaqueAlreadyEncoded()` method should no longer be used. Instead, call `SetEncoded(true)` on a mesage.Buffer and then call `Opaque()` to archive the same result.
+ * Calls to `message.Buffer`'s `Opaque()` and `Multipart()` methods are now guaranteed to work if called repeatedly.
+ * Add the `Buffer.SetMultipart` method for setting the `message.BufferMode` of a `message.Buffer` to `message.ModeMultipart` and setting the capacity of the internal parts slice.
+ * It is now possible to use message.Buffer as a `message.Part` directly.
+ * Add the `Buffer.SetOpaque` method for setting the `message.BufferMode` of a `message.Buffer` to `message.ModeOpaque`.
+ * Add a linter to check changelog correctness.
+ * Add a linter to check for bad patterns in golang.
+ * Add tools to manage the release process.
+
+v2.0.3  2023-01-22
+
+ * Bugfix: Base64 transfer encoding inserts line breaks at column 76 now.
+ * Bugfix: `AttachmentFile` now sets `Content-disposition` to `attachment` and sets the `filename` parameter correctly.
+ * Bugfix: Junk at the start of the message is more recoverable than it was. The message parsed without junk will be returned with the `field.BadStartError`.
+ * Add `Clone()` method to `field.Field`, `header.Base`, and `header.Header`
+ * More test coverage for transfer encoding support.
+ * More test coverage for `message.Opaque` features.
+ * More test coverage for `message.Parse` features.
+
+v2.0.2  2023-01-19
+
+ * Docfix: Made some additional correction to examples in the docs.
+
+v2.0.1  2023-01-18
+
+ * Docfix: Fixed a missing return in an example in the docs.
+
+v2.0.0  2023-01-18
+
+ * Major rewrite of the original. This is the first official, tagged release.
+ * Provides support for parsing via `message.Parse()`
+ * Containers for messages are `message.Opaque` for any kind of message or message part and `message.Multipart` for MIME multipart messages and parts.
+ * Provide `message.Buffer` for creating new messages.
+ * The header package provides high- and mid-level access to email message headers.
+ * The field package provides low-level access to email message header fields.
+ * The transfer package provides transfer encoding support.
+ * The encoding package enables full charset support (at the cost of a much larger compiled binary).
+ * The param package provides support for parameterized header field bodies as are used for `Content-type` and `Content-disposition` headers.
+ * The walker package provides experimental support for iterating through message parts.
+
+v1.0.0  2022-12-05
+
+ * Unofficial tagged release.

message/header/header.go

@@ -116,18 +116,36 @@ func (h *Header) setValue(name string, value any) {
 //
 // If the named field is not set in the header, it will return an empty string
 // with ErrNoSuchField. If there are multiple headers for the given named field,
-// it will return ErrManyFields.
+// it will return the first value found and return ErrManyFields.
 func (h *Header) Get(name string) (string, error) {
 	ixs := h.GetIndexesNamed(name)
 	if len(ixs) == 0 {
 		return "", ErrNoSuchField
 	}
 
+	b := h.GetField(ixs[0]).Body()
 	if len(ixs) > 1 {
-		return "", ErrManyFields
+		return b, ErrManyFields
 	}
 
-	return h.GetField(ixs[0]).Body(), nil
+	return b, nil
+}
+
+// ParseTime is a function that provides the time parsing used by GetTime() and
+// GetDate() to parse dates to be used on any field body. This will attempt to
+// parse the date using the format specified by RFC 5322 first and fallback to
+// parsing it in many other formats.
+//
+// It either returns a parsed time or the parse error.
+func ParseTime(body string) (time.Time, error) {
+	t, err := mail.ParseDate(body)
+	if err != nil {
+		t, err = dateparse.ParseAny(body)
+		if err != nil {
+			return t, err
+		}
+	}
+	return t, nil
 }
 
 // getTime parses the header body as a date and caches the result.
@@ -137,12 +155,9 @@ func (h *Header) getTime(name string) (time.Time, error) {
 		return time.Time{}, err
 	}
 
-	t, err := mail.ParseDate(body)
+	t, err := ParseTime(body)
 	if err != nil {
-		t, err = dateparse.ParseAny(body)
-		if err != nil {
-			return t, err
-		}
+		return t, err
 	}
 
 	h.setValue(name, t)
@@ -172,6 +187,24 @@ func (h *Header) GetTime(name string) (time.Time, error) {
 	return t, nil
 }
 
+// ParseAddressList provides the same address parsing functionality build into
+// the GetAddressList() and GetAllAddressLists() and can be used to parse any
+// field body. It will attempt a strict parse of the email address list.
+// However, if that fails, an extremely lenient parsing will be attempted, which
+// might result in results that can only be described as "weird" in the effort
+// to provide some kind of result. It is so forgiving, it will return some kind
+// of value for any input.
+//
+// It will either return an addr.AddressList or an error describing the parse error.
+func ParseAddressList(body string) addr.AddressList {
+	al, err := addr.ParseEmailAddressList(body)
+	if err != nil {
+		al = parseEmailAddressList(body)
+	}
+
+	return al
+}
+
 // getAddressList will parse an addr.AddressList out of the field or return an
 // error. This falls back onto parseEmailAddressList() if
 // addr.ParseEmailAddrList() lets us down.
@@ -181,11 +214,7 @@ func (h *Header) getAddressList(name string) (addr.AddressList, error) {
 		return nil, err
 	}
 
-	al, err := addr.ParseEmailAddressList(body)
-	if err != nil {
-		al = parseEmailAddressList(body)
-	}
-
+	al := ParseAddressList(body)
 	h.setValue(name, al)
 
 	return al, nil
@@ -222,11 +251,7 @@ func (h *Header) getAllAddressLists(name string) ([]addr.AddressList, error) {
 
 	allAl := make([]addr.AddressList, 0, 10)
 	for _, b := range bs {
-		al, err := addr.ParseEmailAddressList(b)
-		if err != nil {
-			al = parseEmailAddressList(b)
-		}
-
+		al := ParseAddressList(b)
 		allAl = append(allAl, al)
 	}
 

tools/pm/cmd/extract-changelog.go

@@ -8,6 +8,7 @@ import (
 	"github.com/spf13/cobra"
 
 	"github.com/zostay/go-email/v2/tools/pm/changes"
+	"github.com/zostay/go-email/v2/tools/pm/release"
 )
 
 var (
@@ -20,7 +21,7 @@ var (
 )
 
 func ExtractChangelog(_ *cobra.Command, args []string) {
-	r, err := changes.ExtractSection("Changes", args[0])
+	r, err := changes.ExtractSection(release.GoEmailConfig.Changelog, args[0])
 	if err != nil {
 		_, _ = fmt.Fprintf(os.Stderr, "Failed to read changelog section: %v\n", err)
 		os.Exit(1)

tools/pm/cmd/lint-changelog.go

@@ -7,6 +7,7 @@ import (
 	"github.com/spf13/cobra"
 
 	"github.com/zostay/go-email/v2/tools/pm/changes"
+	"github.com/zostay/go-email/v2/tools/pm/release"
 )
 
 var (
@@ -27,7 +28,7 @@ func init() {
 }
 
 func LintChangelog(_ *cobra.Command, _ []string) {
-	changelog, err := os.Open("Changes")
+	changelog, err := os.Open(release.GoEmailConfig.Changelog)
 	if err != nil {
 		_, _ = fmt.Fprintf(os.Stderr, "unable to open Changes file: %v", err)
 		os.Exit(1)

tools/pm/release/config.go

@@ -40,7 +40,7 @@ type Config struct {
 }
 
 var GoEmailConfig = Config{
-	Changelog: "Changes",
+	Changelog: "Changes.md",
 	Owner:     "zostay",
 	Project:   "go-email",