first commit

.github/dependabot.yaml

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+#
+# Do not edit. This file was generated via the "workflow" command line tool.
+# More information about the tool can be found at github.com/xh3b4sd/workflow.
+#
+#     workflow create dependabot -b master -r xh3b4sd
+#
+
+version: 2
+updates:
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    ignore:
+      - dependency-name: "*"
+        update-types: ["version-update:semver-patch"]
+    open-pull-requests-limit: 10
+    reviewers:
+      - "xh3b4sd"
+    schedule:
+      interval: "daily"
+      time: "04:00"
+    target-branch: "master"
+
+  - package-ecosystem: "gomod"
+    directory: "/"
+    ignore:
+      - dependency-name: "*"
+        update-types: ["version-update:semver-patch"]
+    open-pull-requests-limit: 10
+    reviewers:
+      - "xh3b4sd"
+    schedule:
+      interval: "daily"
+      time: "04:00"
+    target-branch: "master"

.github/workflows/go-build.yaml

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+#
+# Do not edit. This file was generated via the "workflow" command line tool.
+# More information about the tool can be found at github.com/xh3b4sd/workflow.
+#
+#     workflow create golang
+#
+
+name: "go-build"
+
+on: "push"
+
+jobs:
+  go-build:
+    runs-on: "ubuntu-latest"
+    steps:
+
+      - name: "Setup Git Project"
+        uses: "actions/checkout@v4"
+
+      - name: "Setup Go Env"
+        uses: "actions/setup-go@v4"
+        with:
+          cache: true
+          go-version: "1.21.1"
+
+      - name: "Check Go Dependencies"
+        run: |
+          go mod tidy
+          git diff --exit-code
+
+      - name: "Check Go Tests"
+        run: |
+          go test ./... -race
+
+      - name: "Check Go Formatting"
+        run: |
+          test -z $(gofmt -l -s .)
+
+      - name: "Check Go Linters"
+        run: |
+          curl -LOs https://github.com/golangci/golangci-lint/releases/download/v1.54.2/golangci-lint-1.54.2-linux-amd64.tar.gz
+          tar -xzf golangci-lint-1.54.2-linux-amd64.tar.gz
+          ./golangci-lint-1.54.2-linux-amd64/golangci-lint run

.gitignore

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+/.vscode/

LICENSE

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+MIT License
+
+Copyright (c) 2023 xh3b4sd
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# logger
+
+Simple structured logging with severity awareness. Logging is one essential
+observability technique in order to not fly blindly. Structuring logs is simple
+and yet powerful because it supports different formats that can be addapted to
+any application's needs.
+
+
+
+### Log Level Awareness
+
+There are 4 log levels supported, namely `debug`, `info`, `warning` and `error`.
+Logs are emitted based on filter configurations provided to the logger creation.
+Below is shown which logger setting causes which behaviour of emitted logs.
+
+logger setting | emitted logs
+---|---
+`debug` | `debug`, `info`, `warning`, `error`
+`info` | `info`, `warning`, `error`
+`warning` | `warning`, `error`
+`error` | `error`
+
+
+
+### Logging In Code
+
+Below is an example of emitting `info` logs providing information of expected
+business logic behaviour.
+
+```golang
+r.log.Log(ctx, "level", "info", "message", "something important happened")
+```
+
+Below is an example of emitting `error` logs providing information of unexpected
+business logic behaviour. Note that stack trace logging is wel integrated with
+[tracer](https://github.com/xh3b4sd/tracer).
+
+```golang
+r.log.Log(ctx, "level", "error", "message", "something bad happened", "stack", tracer.Stack(err))
+```
+
+
+
+### Log Line Printing
+
+Using `logger` prints log lines like shown in the example below. Note that you
+can configure the `io.Writer` that actually handles the byte streams. The
+default is configured to be `os.Stdout`.
+
+```json
+{
+  "time": "2006-01-02 15:04:05",
+  "leve": "info",
+  "mess": "something important happened",
+  "stac": [
+    "--REPLACED--/logger_test.go:104",
+    "--REPLACED--/logger_test.go:105"
+  ],
+  "call": "--REPLACED--/logger_test.go:129"
+}
+```

caller.go

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+package logger
+
+import (
+	"fmt"
+	"runtime"
+)
+
+var EmptyCaller = func() string {
+	return ""
+}
+
+var DefaultCaller = func() string {
+	_, file, line, _ := runtime.Caller(2)
+	return fmt.Sprintf("%s:%d", file, line)
+}

error.go

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+package logger
+
+import (
+	"errors"
+
+	"github.com/xh3b4sd/tracer"
+)
+
+var invalidConfigError = &tracer.Error{
+	Kind: "invalidConfigError",
+}
+
+func IsInvalidConfig(err error) bool {
+	return errors.Is(err, invalidConfigError)
+}

factory.go

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+package logger
+
+func Default() Interface {
+	return New(Config{})
+}
+
+func Fake() Interface {
+	return fake{}
+}

fake.go

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+package logger
+
+import "context"
+
+type fake struct{}
+
+func (r fake) Log(ctx context.Context, pai ...string) {}

filter.go

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+package logger
+
+import "context"
+
+var EmptyFilter = func(context.Context, map[string]string) bool { return false }
+
+var DefaultFilter = NewLevelFilter(LevelInfo)

formatter.go

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+package logger
+
+import (
+	"context"
+	"sort"
+	"strings"
+
+	"github.com/xh3b4sd/logger/meta"
+)
+
+var DefaultFormatter = JSONFormatter
+
+// JSONFormatter transforms the given map into the string representation of a
+// simple JSON object. One specificity of JSONFormatter is that it treats the
+// value of key "stack" differently. In case a key-value pair with the key
+// "stack" is provided, the associated value is treated like a JSON object, and
+// not like a JSON string. This difference in behaviour is unique compared to
+// all other key-value pairs map may carry with it.
+func JSONFormatter(c context.Context, m map[string]string) string {
+	// Once we have the full map of key-value pairs we need the keys only in
+	// order to sort them. We want the emitted log line to be alphabetically
+	// ordered by keys.
+	var ctx []string
+	var oth []string
+	{
+		for k := range m {
+			if k == KeyCal || k == KeyLev || k == KeyMes || k == KeySta || k == KeyTim {
+				continue
+			}
+
+			if meta.Has(c, k) {
+				ctx = append(ctx, k)
+			} else {
+				oth = append(oth, k)
+			}
+		}
+
+		sort.Strings(ctx)
+		sort.Strings(oth)
+	}
+
+	var key func(string) string
+	{
+		key = func(k string) string {
+			if k == KeyCal || k == KeyCod || k == KeyDes || k == KeyDoc || k == KeyLev || k == KeyMes || k == KeySta || k == KeyTim {
+				return k[:4]
+			}
+
+			return k
+		}
+	}
+
+	var val func(string) string
+	{
+		val = func(k string) string {
+			v, e := m[k]
+			if !e {
+				return ""
+			}
+
+			if k == KeyLev {
+				return v[:4]
+			}
+
+			return v
+		}
+	}
+
+	var bui func(string) string
+	{
+		bui = func(k string) string {
+			var s string
+
+			s += "\""
+			s += key(k)
+			s += "\""
+			s += ":"
+
+			if k != KeySta {
+				s += "\""
+			}
+
+			s += val(k)
+
+			if k != KeySta {
+				s += "\""
+			}
+
+			return s
+		}
+	}
+
+	// Below we compute a JSON string for the structured log line we want to
+	// emit.
+	var s string
+	{
+		{
+			s += "{ "
+		}
+
+		{
+			s += bui(KeyTim)
+			s += ", "
+			s += bui(KeyLev)
+			s += ", "
+		}
+
+		{
+			for _, k := range ctx {
+				s += bui(k)
+				s += ", "
+			}
+		}
+
+		{
+			s += bui(KeyMes)
+		}
+
+		{
+			for i, k := range oth {
+				if i == 0 {
+					s += ", "
+				}
+				if m[k] == "" {
+					continue
+				}
+				s += bui(k)
+				if i+1 < len(oth) {
+					s += ", "
+				}
+			}
+		}
+
+		{
+			_, e := m[KeySta]
+			if e {
+				if !strings.HasSuffix(s, ", ") {
+					s += ", "
+				}
+				s += bui(KeySta)
+			}
+		}
+
+		{
+			_, e := m[KeyCal]
+			if e {
+				if !strings.HasSuffix(s, ", ") {
+					s += ", "
+				}
+				s += bui(KeyCal)
+			}
+		}
+
+		{
+			s += " }"
+		}
+	}
+
+	return s
+}

go.mod

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+module github.com/xh3b4sd/logger
+
+go 1.21
+
+require (
+	github.com/google/go-cmp v0.6.0
+	github.com/xh3b4sd/tracer v0.11.1
+)
+
+retract [v0.0.0, v0.8.0]