feat: parse flag values strictly in built-in providers

CHANGELOG.md

@@ -11,15 +11,21 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - The `API` service is now an isolated `OpenFeatureAPI` instance created by the container (SDK 2.3.0 isolated instances) instead of the `OpenFeatureAPI::getInstance()` global singleton. Provider, hooks, and evaluation context are no longer shared with other kernels running in the same PHP process.
 - `open-feature/sdk` requirement raised from `^2.2` to `^2.3` (the bundle relies on the public `OpenFeatureAPI` constructor introduced in SDK 2.3.0).
+- `EnvVarProvider` and `RedisProvider` now return a `PARSE_ERROR` (and the default value) for raw values that do not match the requested type, instead of silently casting them (`"abc"` as integer used to resolve to `0`, `"banana"` as boolean to `false`).
+- `InMemoryProvider` returns a `TYPE_MISMATCH` instead of casting for integers other than `0`/`1` requested as boolean (e.g. `2` or `-1`, previously `true`), non-string values requested as string (e.g. `42`, previously `"42"`), and floats requested as integer (e.g. `1.5`, previously `1`).
+- `ResolutionDetailsTrait::toBool()` is replaced by `parseBool()`, `parseInt()`, `parseFloat()`, and `parseObject()`.
 
 ### Fixed
 
 - `flags` and `providers`: keys are now kept as declared. Dashes were converted to underscores (a flag declared as `new-checkout` could only be evaluated as `new_checkout`), and an object flag holding a `name` key was renamed after that value. The undocumented list form `flags: [{name: ..., value: ...}]` is no longer supported.
+- `RedisProvider` now logs Redis client failures at `error` level. Previously, an unavailable Redis silently resolved every flag to its default value, with nothing in the logs.
 
 ### Upgrade notes
 
 - Run `composer update open-feature/sdk` if your lock file pins a version below 2.3.0.
 - Code calling `OpenFeatureAPI::getInstance()` directly now gets an instance distinct from the bundle's `API` service (different provider, hooks, and evaluation context). Inject the `API` or `Client` service instead.
+- **Check your raw flag values.** `EnvVarProvider` and `RedisProvider` no longer cast unparsable values: a boolean flag set to anything other than `true`/`false`/`1`/`0`/`yes`/`no`/`on`/`off`/empty (e.g. `FEATURE_X=enabled`, previously `false`) or a numeric flag with a non-numeric value (for integers, decimal or exponent notation such as `10.0` or `1e3` too; leading zeros such as `08` are accepted) now resolves to the default value with a `PARSE_ERROR`. `InMemoryProvider` flags declared with a mismatching type (e.g. `max_items: 1.5` read as integer, `label: 42` read as string) now resolve to the default value with a `TYPE_MISMATCH`, like with typed providers such as flagd. In Twig, `{{ feature_value('max_items') }}` without a default reads the flag as a string and now renders `''`: pass a typed default (`feature_value('max_items', 10)`). These errors are not logged by the SDK: check the `open_feature` profiler panel in dev (error column), or register a hook that logs `ResolutionDetails::getError()` in `after()`.
+- Custom providers using `ResolutionDetailsTrait::toBool()` must switch to `parseBool($flagKey, $raw, $defaultValue)`, which returns a `ResolutionDetails` instead of a `bool`.
 
 ## [0.3.0] - 2026-06-15
 

docs/features/twig.md

@@ -30,4 +30,6 @@ The SDK method is dispatched based on the type of the default value:
 | `float` | `getFloatValue()` |
 | `array` | `getObjectValue()` |
 
+Always pass a default of the flag's type. Without a default, the flag is read as a string: a boolean or integer flag then resolves to `''` with a `TYPE_MISMATCH` error, as typed providers such as flagd do.
+
 > **Note:** The Twig extension is only registered when `twig/twig` is available in the project.

docs/providers/env-var.md

@@ -33,8 +33,14 @@ FEATURE_MAX_ITEMS=10
 FEATURE_CONFIG='{"color":"blue"}'
 ```
 
-Boolean truthy values: `true`, `1`, `yes`, `on`.
+| Requested type | Accepted raw values |
+|---|---|
+| boolean | `true`/`false`, `1`/`0`, `yes`/`no`, `on`/`off` (case-insensitive), empty string (`false`) |
+| integer | whole numbers with an optional sign; leading zeros allowed (`08`), no decimal or exponent notation (`10.0`, `1e3`) |
+| float | any numeric notation (`3.14`, `08`, `1e3`) |
+| string | any value |
+| object | a JSON object or array |
 
-Object values must be JSON-encoded. Invalid JSON returns the default value with `ErrorCode::PARSE_ERROR`.
+Any other raw value returns the default value with `ErrorCode::PARSE_ERROR` (e.g. `FEATURE_X=enabled` read as boolean).
 
 If the environment variable is not set, the provider returns the default value with `ErrorCode::FLAG_NOT_FOUND`.

docs/providers/in-memory.md

@@ -24,9 +24,11 @@ A flag value must be resolved with the method matching its YAML type:
 
 | YAML value | Resolved via |
 |---|---|
-| `true` / `false` | `getBooleanValue()` (also readable as `getStringValue()`) |
-| `42` | `getIntegerValue()` or `getFloatValue()` (also readable as `getStringValue()`) |
+| `true` / `false` | `getBooleanValue()` |
+| `0` / `1` | `getBooleanValue()` (as `false` / `true`), `getIntegerValue()` or `getFloatValue()` |
+| `42` | `getIntegerValue()` or `getFloatValue()` |
+| `1.5` | `getFloatValue()` |
 | `"dark"` | `getStringValue()` |
-| `{color: blue}` | `getObjectValue()` |
+| `{color: blue}` or a list | `getObjectValue()` |
 
-Any other combination returns the default value with `ErrorCode::TYPE_MISMATCH`.
+Any other combination returns the default value with `ErrorCode::TYPE_MISMATCH`. No value is cast to string: read a boolean or numeric flag with its own method.

docs/providers/redis.md

@@ -46,10 +46,18 @@ feature:config        ->  '{"color":"blue"}'
 
 ## Values
 
-Boolean truthy values: `true`, `1`, `yes`, `on`.
+| Requested type | Accepted raw values |
+|---|---|
+| boolean | `true`/`false`, `1`/`0`, `yes`/`no`, `on`/`off` (case-insensitive), empty string (`false`) |
+| integer | whole numbers with an optional sign; leading zeros allowed (`08`), no decimal or exponent notation (`10.0`, `1e3`) |
+| float | any numeric notation (`3.14`, `08`, `1e3`) |
+| string | any value |
+| object | a JSON object or array |
 
-Object values must be JSON-encoded. Invalid JSON returns the default value with `ErrorCode::PARSE_ERROR`.
+Any other raw value returns the default value with `ErrorCode::PARSE_ERROR` (e.g. `"enabled"` read as boolean).
 
 ## Error handling
 
 If Redis is unavailable, the provider returns the default value with an error reason (`ErrorCode::GENERAL`) instead of throwing an exception. This makes it safe to use in production without risking a full outage if Redis goes down.
+
+Each failure is logged at `error` level with the exception, so an outage shows up in your logs. During an outage, this means one log entry per flag evaluation: use Monolog's `fingers_crossed` or deduplication handlers if the volume is a concern.

src/Provider/EnvVarProvider.php

@@ -6,7 +6,6 @@
 
 use OpenFeature\implementation\provider\AbstractProvider;
 use OpenFeature\interfaces\flags\EvaluationContext;
-use OpenFeature\interfaces\provider\ErrorCode;
 use OpenFeature\interfaces\provider\Provider;
 use OpenFeature\interfaces\provider\ResolutionDetails;
 
@@ -32,7 +31,7 @@ public function resolveBooleanValue(string $flagKey, bool $defaultValue, ?Evalua
             return $this->flagNotFound($flagKey, $defaultValue);
         }
 
-        return $this->found($this->toBool($raw));
+        return $this->parseBool($flagKey, $raw, $defaultValue);
     }
 
     public function resolveStringValue(string $flagKey, string $defaultValue, ?EvaluationContext $context = null): ResolutionDetails
@@ -54,7 +53,7 @@ public function resolveIntegerValue(string $flagKey, int $defaultValue, ?Evaluat
             return $this->flagNotFound($flagKey, $defaultValue);
         }
 
-        return $this->found((int) $raw);
+        return $this->parseInt($flagKey, $raw, $defaultValue);
     }
 
     public function resolveFloatValue(string $flagKey, float $defaultValue, ?EvaluationContext $context = null): ResolutionDetails
@@ -65,7 +64,7 @@ public function resolveFloatValue(string $flagKey, float $defaultValue, ?Evaluat
             return $this->flagNotFound($flagKey, $defaultValue);
         }
 
-        return $this->found((float) $raw);
+        return $this->parseFloat($flagKey, $raw, $defaultValue);
     }
 
     /**
@@ -79,13 +78,7 @@ public function resolveObjectValue(string $flagKey, array $defaultValue, ?Evalua
             return $this->flagNotFound($flagKey, $defaultValue);
         }
 
-        $decoded = \json_decode($raw, true);
-
-        if (!\is_array($decoded)) {
-            return $this->error(ErrorCode::PARSE_ERROR(), \sprintf('Flag "%s" contains invalid JSON', $flagKey), $defaultValue);
-        }
-
-        return $this->found($decoded);
+        return $this->parseObject($flagKey, $raw, $defaultValue);
     }
 
     private function getEnvVar(string $flagKey): ?string

src/Provider/InMemoryProvider.php

@@ -29,7 +29,8 @@ public function resolveBooleanValue(string $flagKey, bool $defaultValue, ?Evalua
 
         $value = $this->flags[$flagKey];
 
-        if (!\is_bool($value) && !\is_int($value)) {
+        // 0/1 accepted for YAML convenience; other integers are ambiguous
+        if (!\is_bool($value) && $value !== 0 && $value !== 1) {
             return $this->error(ErrorCode::TYPE_MISMATCH(), \sprintf('Flag "%s" is not of type boolean', $flagKey), $defaultValue);
         }
 
@@ -44,11 +45,11 @@ public function resolveStringValue(string $flagKey, string $defaultValue, ?Evalu
 
         $value = $this->flags[$flagKey];
 
-        if (!\is_scalar($value)) {
+        if (!\is_string($value)) {
             return $this->error(ErrorCode::TYPE_MISMATCH(), \sprintf('Flag "%s" is not of type string', $flagKey), $defaultValue);
         }
 
-        return $this->found((string) $value);
+        return $this->found($value);
     }
 
     public function resolveIntegerValue(string $flagKey, int $defaultValue, ?EvaluationContext $context = null): ResolutionDetails
@@ -59,11 +60,11 @@ public function resolveIntegerValue(string $flagKey, int $defaultValue, ?Evaluat
 
         $value = $this->flags[$flagKey];
 
-        if (!\is_int($value) && !\is_float($value)) {
+        if (!\is_int($value)) {
             return $this->error(ErrorCode::TYPE_MISMATCH(), \sprintf('Flag "%s" is not of type integer', $flagKey), $defaultValue);
         }
 
-        return $this->found((int) $value);
+        return $this->found($value);
     }
 
     public function resolveFloatValue(string $flagKey, float $defaultValue, ?EvaluationContext $context = null): ResolutionDetails

src/Provider/RedisProvider.php

@@ -27,96 +27,55 @@ public function __construct(
 
     public function resolveBooleanValue(string $flagKey, bool $defaultValue, ?EvaluationContext $context = null): ResolutionDetails
     {
-        try {
-            $raw = $this->getRaw($flagKey);
-        } catch (\RuntimeException $e) {
-            return $this->error(ErrorCode::GENERAL(), \sprintf('Flag "%s": %s', $flagKey, $e->getMessage()), $defaultValue);
-        }
-
-        if ($raw === null) {
-            return $this->flagNotFound($flagKey, $defaultValue);
-        }
-
-        return $this->found($this->toBool($raw));
+        return $this->resolveRaw($flagKey, $defaultValue, fn (string $raw) => $this->parseBool($flagKey, $raw, $defaultValue));
     }
 
     public function resolveStringValue(string $flagKey, string $defaultValue, ?EvaluationContext $context = null): ResolutionDetails
     {
-        try {
-            $raw = $this->getRaw($flagKey);
-        } catch (\RuntimeException $e) {
-            return $this->error(ErrorCode::GENERAL(), \sprintf('Flag "%s": %s', $flagKey, $e->getMessage()), $defaultValue);
-        }
-
-        if ($raw === null) {
-            return $this->flagNotFound($flagKey, $defaultValue);
-        }
-
-        return $this->found($raw);
+        return $this->resolveRaw($flagKey, $defaultValue, fn (string $raw) => $this->found($raw));
     }
 
     public function resolveIntegerValue(string $flagKey, int $defaultValue, ?EvaluationContext $context = null): ResolutionDetails
     {
-        try {
-            $raw = $this->getRaw($flagKey);
-        } catch (\RuntimeException $e) {
-            return $this->error(ErrorCode::GENERAL(), \sprintf('Flag "%s": %s', $flagKey, $e->getMessage()), $defaultValue);
-        }
-
-        if ($raw === null) {
-            return $this->flagNotFound($flagKey, $defaultValue);
-        }
-
-        return $this->found((int) $raw);
+        return $this->resolveRaw($flagKey, $defaultValue, fn (string $raw) => $this->parseInt($flagKey, $raw, $defaultValue));
     }
 
     public function resolveFloatValue(string $flagKey, float $defaultValue, ?EvaluationContext $context = null): ResolutionDetails
     {
-        try {
-            $raw = $this->getRaw($flagKey);
-        } catch (\RuntimeException $e) {
-            return $this->error(ErrorCode::GENERAL(), \sprintf('Flag "%s": %s', $flagKey, $e->getMessage()), $defaultValue);
-        }
-
-        if ($raw === null) {
-            return $this->flagNotFound($flagKey, $defaultValue);
-        }
-
-        return $this->found((float) $raw);
+        return $this->resolveRaw($flagKey, $defaultValue, fn (string $raw) => $this->parseFloat($flagKey, $raw, $defaultValue));
     }
 
     /**
      * @param mixed[] $defaultValue
      */
     public function resolveObjectValue(string $flagKey, array $defaultValue, ?EvaluationContext $context = null): ResolutionDetails
     {
-        try {
-            $raw = $this->getRaw($flagKey);
-        } catch (\RuntimeException $e) {
-            return $this->error(ErrorCode::GENERAL(), \sprintf('Flag "%s": %s', $flagKey, $e->getMessage()), $defaultValue);
-        }
-
-        if ($raw === null) {
-            return $this->flagNotFound($flagKey, $defaultValue);
-        }
-
-        $decoded = \json_decode($raw, true);
-
-        if (!\is_array($decoded)) {
-            return $this->error(ErrorCode::PARSE_ERROR(), \sprintf('Flag "%s" contains invalid JSON', $flagKey), $defaultValue);
-        }
-
-        return $this->found($decoded);
+        return $this->resolveRaw($flagKey, $defaultValue, fn (string $raw) => $this->parseObject($flagKey, $raw, $defaultValue));
     }
 
-    private function getRaw(string $flagKey): ?string
+    /**
+     * @param bool|float|int|mixed[]|string       $defaultValue
+     * @param \Closure(string): ResolutionDetails $parse
+     */
+    private function resolveRaw(string $flagKey, bool|string|int|float|array $defaultValue, \Closure $parse): ResolutionDetails
     {
         try {
-            $value = $this->client->get($this->prefix . $flagKey);
+            $raw = $this->client->get($this->prefix . $flagKey);
         } catch (\Throwable $e) {
-            throw new \RuntimeException($e->getMessage(), previous: $e);
+            // The SDK does not log errors returned in ResolutionDetails
+            $this->logger?->error('OpenFeature Redis provider failed to read flag "{flag}": {message}', [
+                'flag' => $flagKey,
+                'message' => $e->getMessage(),
+                'exception' => $e,
+            ]);
+
+            return $this->error(ErrorCode::GENERAL(), \sprintf('Flag "%s": %s', $flagKey, $e->getMessage()), $defaultValue);
+        }
+
+        if ($raw === false || $raw === null) {
+            return $this->flagNotFound($flagKey, $defaultValue);
         }
 
-        return ($value === false || $value === null) ? null : $value;
+        return $parse($raw);
     }
 }

src/Provider/ResolutionDetailsTrait.php

@@ -41,8 +41,43 @@ private function error(ErrorCode $code, string $message, bool|string|int|float|a
             ->build();
     }
 
-    private function toBool(string $value): bool
+    /**
+     * Accepts true/false, 1/0, yes/no, on/off (case-insensitive) and the empty string (false).
+     */
+    private function parseBool(string $flagKey, string $raw, bool $defaultValue): ResolutionDetails
     {
-        return \in_array(\strtolower($value), ['true', '1', 'yes', 'on'], true);
+        $value = \filter_var($raw, \FILTER_VALIDATE_BOOL, \FILTER_NULL_ON_FAILURE);
+
+        return $value === null ? $this->parseError($flagKey, 'boolean', $defaultValue) : $this->found($value);
+    }
+
+    private function parseInt(string $flagKey, string $raw, int $defaultValue): ResolutionDetails
+    {
+        // Leading zeros are accepted ("08"), as FILTER_VALIDATE_FLOAT already does
+        $normalized = \preg_replace('/^([+-]?)0+(?=\d)/', '$1', \trim($raw));
+        $value = \filter_var($normalized, \FILTER_VALIDATE_INT, \FILTER_NULL_ON_FAILURE);
+
+        return $value === null ? $this->parseError($flagKey, 'integer', $defaultValue) : $this->found($value);
+    }
+
+    private function parseFloat(string $flagKey, string $raw, float $defaultValue): ResolutionDetails
+    {
+        $value = \filter_var($raw, \FILTER_VALIDATE_FLOAT, \FILTER_NULL_ON_FAILURE);
+
+        return $value === null ? $this->parseError($flagKey, 'float', $defaultValue) : $this->found($value);
+    }
+
+    /** @param mixed[] $defaultValue */
+    private function parseObject(string $flagKey, string $raw, array $defaultValue): ResolutionDetails
+    {
+        $value = \json_decode($raw, true);
+
+        return \is_array($value) ? $this->found($value) : $this->parseError($flagKey, 'JSON object', $defaultValue);
+    }
+
+    /** @param bool|float|int|mixed[]|string $defaultValue */
+    private function parseError(string $flagKey, string $type, bool|string|int|float|array $defaultValue): ResolutionDetails
+    {
+        return $this->error(ErrorCode::PARSE_ERROR(), \sprintf('Flag "%s" is not a valid %s', $flagKey, $type), $defaultValue);
     }
 }