🚀 3.1.0: Add fallback option

Author: DZakh

README.md

@@ -50,7 +50,7 @@ let nodeEnv = envSafe->EnvSafe.get(
   ]),
   ~devFallback=#development,
 )
-let port = envSafe->EnvSafe.get("PORT", S.int->S.Int.port, ~devFallback=3000)
+let port = envSafe->EnvSafe.get("PORT", S.int->S.Int.port, ~fallback=3000)
 let apiUrl = envSafe->EnvSafe.get("API_URL", S.string->S.String.url, ~devFallback="https://example.com/graphql")
 let auth0ClientId = envSafe->EnvSafe.get("AUTH0_CLIENT_ID", S.string)
 let auth0Domain = envSafe->EnvSafe.get("AUTH0_DOMAIN", S.string)
@@ -73,10 +73,10 @@ Creates `envSafe` to start working with environment variables. By default it use
 
 ### **`EnvSafe.get`**
 
-`(EnvSafe.t, string, S.t<'value>, ~allowEmpty: bool=?, ~devFallback: 'value=?, ~input: option<string>=?) => 'value`
+`(EnvSafe.t, string, S.t<'value>, ~allowEmpty: bool=?, ~fallback: 'value=?, ~devFallback: 'value=?, ~input: option<string>=?) => 'value`
 
 ```rescript
-let port = envSafe->EnvSafe.get("PORT", S.int->S.Int.port, ~devFallback=3000)
+let port = envSafe->EnvSafe.get("PORT", S.int->S.Int.port, ~fallback=3000)
 ```
 
 Gets an environment variable from `envSafe` applying coercion and parsing logic of `schema`.
@@ -87,7 +87,8 @@ Gets an environment variable from `envSafe` applying coercion and parsing logic
 | ------------- | ------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `name`        | `string`      | Name of the environment variable                                                                                                                                                                                                                                                                                                                              |
 | `schema`      | `S.t<'value>` | A schema created with **[rescript-schema](https://github.com/DZakh/rescript-schema)**. It's used for coercion and parsing. For bool schemas coerces `"0", "1", "true", "false", "t", "f"` to boolean values. For int and float schemas coerces string to number. For other non-string schemas the value is coerced using `JSON.parse` before being validated. |
-| `devFallback` | `'value=?`    | A fallback value to use only when `NODE_ENV` is not `production`. This is handy for env vars that are required for production environments, but optional for development and testing. If you need to set fallback value for all environments, you can use `S.Option.getOr` on schema.                                                                         |
+| `fallback`    | `'value=?`    | A fallback value when the environment variable is missing.                                                                                                                                                                                                                                                                                                    |
+| `devFallback` | `'value=?`    | A fallback value to use only when `NODE_ENV` is not `production`. This is handy for env vars that are required for production environments, but optional for development and testing.                                                                                                                                                                         |
 | `input`       | `string=?`    | As some environments don't allow you to dynamically read env vars, we can manually put it in as well. Example: `input=%raw("process.env.NEXT_PUBLIC_API_URL")`.                                                                                                                                                                                               |
 | `allowEmpty`  | `bool=false`  | Default behavior is `false` which treats empty strings as the value is missing. if explicit empty strings are OK, pass in `true`.                                                                                                                                                                                                                             |
 

__tests__/EnvSafe_test.res

@@ -149,6 +149,53 @@ test("Uses devFallback value when env is missing", t => {
   }, ())
 })
 
+test("Uses fallback value when env is missing", t => {
+  let envSafe = EnvSafe.make(
+    ~env=Obj.magic({
+      "STRING_ENV": "abc",
+    }),
+  )
+
+  t->Assert.is(
+    envSafe->EnvSafe.get(
+      "MISSING_ENV",
+      S.literal("invalid")->S.variant(_ => #polymorphicToTestFunctionType2),
+      ~fallback=#polymorphicToTestFunctionType,
+    ),
+    #polymorphicToTestFunctionType,
+    (),
+  )
+  t->Assert.notThrows(() => {
+    envSafe->EnvSafe.close
+  }, ())
+})
+
+type fallbackTestVariant = ReadResult | FallbackResult | DevFallbackResult
+test(
+  "Uses devFallback value over fallback when env is missing and NODE_ENV is not set to production",
+  t => {
+    let envSafe = EnvSafe.make(
+      ~env=Obj.magic({
+        "STRING_ENV": "abc",
+      }),
+    )
+
+    t->Assert.is(
+      envSafe->EnvSafe.get(
+        "MISSING_ENV",
+        S.literal(ReadResult),
+        ~fallback=FallbackResult,
+        ~devFallback=DevFallbackResult,
+      ),
+      DevFallbackResult,
+      (),
+    )
+    t->Assert.notThrows(() => {
+      envSafe->EnvSafe.close
+    }, ())
+  },
+)
+
 test("Doesn't use devFallback value when NODE_ENV is production", t => {
   let envSafe = EnvSafe.make(
     ~env=Obj.magic({
@@ -310,3 +357,23 @@ test("Applies preprocessor logic for union schemas separately", t => {
     envSafe->EnvSafe.close
   }, ())
 })
+
+test("Fails to access EnvSafe after close", t => {
+  let envSafe = EnvSafe.make(
+    ~env=Obj.magic({
+      "STRING_ENV": "abc",
+    }),
+  )
+
+  t->Assert.notThrows(() => {
+    envSafe->EnvSafe.close
+  }, ())
+
+  t->Assert.throws(
+    () => {envSafe->EnvSafe.get("STRING_ENV", S.string)},
+    ~expectations={
+      message: "[rescript-envsafe] EnvSafe is closed. Make a new one to get access to environment variables.",
+    },
+    (),
+  )
+})

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "rescript-envsafe",
-  "version": "3.0.0",
+  "version": "3.1.0",
   "description": "🔒 Makes sure you don't accidentally deploy apps with missing or invalid environment variables",
   "homepage": "https://github.com/DZakh/rescript-envsafe#readme",
   "keywords": [

package.json

@@ -197,6 +197,7 @@ let get = (
   name,
   schema,
   ~allowEmpty=false,
+  ~fallback as maybeFallback=?,
   ~devFallback as maybeDevFallback=?,
   ~input as maybeInlinedInput=?,
 ) => {
@@ -208,13 +209,16 @@ let get = (
   | None => envSafe.env->Stdlib.Dict.get(name)
   }
   let parseResult = input->S.parseAnyWith(prepareSchema(~schema, ~allowEmpty))
-  switch (parseResult, maybeDevFallback) {
-  | (Ok(v), _) => v
-  | (Error({code: InvalidLiteral({received})}), Some(devFallback))
-  | (Error({code: InvalidType({received})}), Some(devFallback))
+  switch (parseResult, maybeDevFallback, maybeFallback) {
+  | (Ok(v), _, _) => v
+  | (Error({code: InvalidLiteral({received})}), Some(devFallback), _)
+  | (Error({code: InvalidType({received})}), Some(devFallback), _)
     if received === %raw(`undefined`) &&
       envSafe.env->Stdlib.Dict.get("NODE_ENV") !== Some("production") => devFallback
-  | (Error(error), _) => {
+  | (Error({code: InvalidLiteral({received})}), _, Some(fallback))
+  | (Error({code: InvalidType({received})}), _, Some(fallback))
+    if received === %raw(`undefined`) => fallback
+  | (Error(error), _, _) => {
       envSafe->mixinIssue({name, error, input})
       %raw(`undefined`)
     }

src/EnvSafe.bs.js

@@ -12,6 +12,7 @@ let get: (
   string,
   S.t<'value>,
   ~allowEmpty: bool=?,
+  ~fallback: 'value=?,
   ~devFallback: 'value=?,
   ~input: option<string>=?,
 ) => 'value