Introduction

ehelper is the utility function module of ee-go, providing common helper features including JSON return value construction, file/directory detection, random string generation, string contains checking, slice deduplication, Map merging, random delay, and random integer generation. These functions cover the most common basic operations in application development, reducing repetitive code writing.

Import

import "github.com/wallace5303/ee-go/ehelper"

API

GetJson()

Description: Create a standard JSON return value struct with default Code as 0, Msg as empty string, and Data as nil. Used for unified HTTP response format.

Parameters: None

Returns: *ResultJson — initialized JSON result struct pointer

Example:

result := ehelper.GetJson()
result.Code = 0
result.Msg = "success"
result.Data = map[string]any{
    "id":   1,
    "name": "example",
}
// Return to frontend
c.JSON(200, result)

See also: ResultJson

---

ResultJson

Description: Unified JSON response struct for HTTP interface return data. Contains three fields: status code, message, and data. Field names are mapped to lowercase via JSON tags.

Field	Type	JSON Tag	Description
Code	int	"code"	Status code, 0 indicates success
Msg	string	"msg"	Message content, can be empty on success
Data	any	"data"	Return data, can be any type

Example:

// Custom response
r := &ehelper.ResultJson{
    Code: -1,
    Msg:  "parameter error",
    Data: nil,
}

---

FileIsExist(path)

Description: Check whether a file or directory exists at the specified path. Returns true if the path exists, false if it doesn't.

Parameters:

Parameter	Type	Required	Description
path	string	Yes	Absolute/relative path of the file or directory

Returns: bool — true if file exists, false if it doesn't

Example:

configPath := "/opt/app/config.json"
if ehelper.FileIsExist(configPath) {
    // Read configuration
} else {
    // Use default configuration
}

---

IsDir(path)

Description: Check whether the specified path is a directory. Returns false if the path doesn't exist or is not a directory.

Parameters:

Parameter	Type	Required	Description
path	string	Yes	Path to check

Returns: bool — true if it's a directory, false if not a directory or path doesn't exist

Example:

path := "/opt/app/data"
if ehelper.IsDir(path) {
    fmt.Println("data is a directory")
} else {
    os.MkdirAll(path, 0755)
}

See also: FileIsExist()

---

GetRandomString(length)

Description: Generate a random string of specified length, with character range including lowercase letters a-z and digits 0-9. There is a 10ns interval between calls to ensure randomness.

Parameters:

Parameter	Type	Required	Description
length	int	Yes	Length of the generated string

Returns: string — random string containing lowercase letters and digits

Example:

// Generate a 16-character random string
token := ehelper.GetRandomString(16)
fmt.Println("Token:", token) // e.g.: "a3b7c9d2e5f8g1h4"

---

Contains(str, strs)

Description: Check whether string str exists in the string slice strs. Compares sequentially, returns true on first match.

Parameters:

Parameter	Type	Required	Description
str	string	Yes	String to search for
strs	[]string	Yes	Target string slice

Returns: bool — true if found, false if not found

Example:

events := []string{"beforeClose", "ready"}
if ehelper.Contains("beforeClose", events) {
    fmt.Println("event is supported")
}

See also: SlicesContains()

---

SlicesContains(slice, str)

Description: Check whether string str exists in the string slice slice. Same functionality as Contains() with different naming style. This function is used uniformly within the framework.

Parameters:

Parameter	Type	Required	Description
slice	[]string	Yes	Target string slice
str	string	Yes	String to search for

Returns: bool — true if found, false if not found

Example:

validEvents := []string{"beforeClose"}
if ehelper.SlicesContains(validEvents, eventName) {
    // Register event
}

See also: Contains()

---

RemoveDuplicatedElem(slice)

Description: Remove duplicate elements from a string slice, keeping the first occurrence of each element, and return the deduplicated new slice. The original slice is not modified.

Parameters:

Parameter	Type	Required	Description
slice	[]string	Yes	String slice to deduplicate

Returns: []string — deduplicated string slice

Example:

names := []string{"alice", "bob", "alice", "charlie", "bob"}
unique := ehelper.RemoveDuplicatedElem(names)
fmt.Println(unique) // ["alice", "bob", "charlie"]

---

Mapserge(src, tgt, itgt)

Description: Merge source Map src into target Map tgt. For keys that already exist in the target Map, if the value is a Map type it is recursively merged, otherwise the source value overwrites the target value. Key name matching is case-insensitive. The optional itgt parameter (type map[any]any) synchronously receives the merge result, for compatibility with Viper's internal map[any]any type data.

Parameters:

Parameter	Type	Required	Description
src	map[string]any	Yes	Source Map, provides the key-value pairs to merge
tgt	map[string]any	Yes	Target Map, receives the merge result
itgt	map[any]any	No	Optional intermediate Map, synchronously receives the merge result; pass nil to skip

Returns: None (directly modifies tgt and itgt)

Example:

// Configuration merge: merge environment configuration into default configuration
defaultCfg := map[string]any{
    "http": map[string]any{
        "port":   8080,
        "enable": true,
    },
}
envCfg := map[string]any{
    "http": map[string]any{
        "port": 9090,
    },
}
ehelper.Mapserge(envCfg, defaultCfg, nil)
// defaultCfg["http"]["port"] is overwritten to 9090
// defaultCfg["http"]["enable"] remains true

---

RandomSleep(minMills, maxMills)

Description: Randomly sleep within a specified time range. Sleep duration is a random value between [minMills, maxMills) milliseconds. Suitable for avoiding concentrated concurrent requests, simulating delay, and similar scenarios.

Parameters:

Parameter	Type	Required	Description
minMills	int	Yes	Minimum sleep time (milliseconds)
maxMills	int	Yes	Maximum sleep time (milliseconds)

Returns: None

Example:

// Randomly sleep 100-500 milliseconds
ehelper.RandomSleep(100, 500)

See also: Int()

---

Int(min, max)

Description: Generate a random integer in the range [min, max). There is a 10ns interval between calls to ensure randomness.

Parameters:

Parameter	Type	Required	Description
min	int	Yes	Lower bound of random number (inclusive)
max	int	Yes	Upper bound of random number (exclusive)

Returns: int — random integer within the range

Example:

// Generate a random number from 1-100
num := ehelper.Int(1, 100)
fmt.Println("Random number:", num)

See also: RandomSleep()